Benchexec

This release brings one major feature for the HTML tables:
The **statistics on the summary tab are now updated on-the-fly**
if filters are applied and always take those filters into account
(i.e., only show statistics about the selected rows).
We update the row name in the statistics table to indicate this,
but still be aware of it if you are accustomed to the previous behavior!
This was also the last place in the HTML tables where filters were not respected,
so now filters are taking into account consistently
wherever data are shown or used.
Thanks to [DennisSimon](https://github.com/DennisSimon) for implementing this!

There are also a few other improvements and fixes:

- Fix loading logs from local HTML tables in Chrome/Chromium.
- Update hint on which Firefox setting to change
for access to logs from local HTML tables.
- When loading logs from local HTML tables fails,
show a hint on how to start a small HTTP server with Python
and let it serve the table and logs.
Using this server to access the table from the browser
instead of `file://` URLs will make the log access work
regardless of browser versions and configuration options.
The shown hint even includes a command line
that just needs to be copy-and-pasted.
- Fix sliders jumping around in the filter sidebar
when defining filters for numeric columns.
- Some tool-info modules were improved.

- Fix bug in HTML tables where content of a cell could be visible
through another cell when scrolling horizontally.
- Slightly improved error handling and error messages
regarding cgroup permissions, cgroupsv2, and invalid directory modes.
- Improved handling of debug log (`--debug`).
Previously, every transferred output file of the tool was logged,
which would lead to large debug logs in case a tool produced many files.
Now we log only the names of at most 1000 such output files.
- Many new and improved tool-info modules.
- The default branch of the git repository has been renamed to `main`.
Please adjust forks and checkouts if required.

the default branch of the repository will be renamed to `main`.
Please adjust forks and checkouts if required.

This release works only on Python 3.6 and newer!

- Add possibility to have a `close()` method to tool-info modules.
- The `test_tool_info` utility now has a `--debug` argument
that will show the debug log, e.g., from the tool-info module.
- Fix bug in detection of CPU throttling during benchmarking,
for which we warn if we detect it.
This did not work for cases with core numbers longer than one digit.
- Properly escape the suggested command line for running table-generator
that is shown by benchexec before it terminates.
- Allow specifying path to libseccomp via environment variable `LIBSECCOMP`.
This is useful for environments like NixOS.
- Fix handling of empty result files in table-generator,
the generated HTML tables will work again.
- Fix handling of empty run results when filtering rows in HTML tables.
- Make filters for status and textual columns in HTML tables work
if filter string contains a colon.
- When entering a filter in the HTML tables' filter row,
do not loose focus on the input field when applying the filter,
such that users can continue typing.
- Fix invalid values shown in score-based quantile plot
if some runs of a table do not have a score value.
Now a run set is only shown in a score-based quantile plot
if all values have scores (otherwise the plot would be misleading).
- Text selection now works as expected while an overlay window is open
in the HTML tables (only text in the overlay will be selected).

This is expected to be the last BenchExec release that supports Python 3.5,
newer releases will require Python 3.6 or newer.
Please [cf. issue 717](https://github.com/sosy-lab/benchexec/issues/717)
for our plan on dropping support for further Python versions.

We would like to note that Linux kernel 5.11
brings a major improvement for BenchExec users not on Ubuntu:
Now it should be possible to use the overlayfs feature as a regular user,
no need to pass `--read-only-dir /` and similar parameters.
We updated our [installation instructions](https://github.com/sosy-lab/benchexec/blob/master/doc/INSTALL.md)
accordingly and also clarified that BenchExec requires x86 or ARM machines
and recommend Linux kernel 4.14 or newer due to reduced cgroups overhead.

Changes in this release:

- In HTML tables, the following settings are now stored in the hash part of the URL:
- Column sorting
- Page size of the table, i.e., how many rows are shown
- Filters for task names that are defined by entering text
into the left-most input field of the filter row of the table.
Previously this would only work for task-name filters defined in the filter sidebar.
This means that using the back/forward navigation of the browser
will change these settings and that they can be present in shared links.
- Fix a few cases of printing of statistics information in HTML tables.
This affects corner cases like the number of visible decimal digits for `0`
and trailing zeroes for the standard deviation in the tooltip.
- When a user requests rounding to a certain number of decimal digits,
the filtering functionality of the HTML tables will now use the raw values,
not the rounded values.
This is consistent with the behavior when rounding is not explicitly requested
and BenchExec applies the default rounding rules.
- Fix harmless stack trace printed at end of `benchexec` execution
in cases like of early termination, e.g., if the tool could not be found.
- Some improvements to tool-info modules.
- Several updates of JS libraries, but this should not bring user-visible changes.

- One tool-info module improved.