Summarytools

- Method for calculating number of bins in `dfSummary()` histograms changed
(from `nclass.FD()` to `nclass.Sturges()`)
- Removed extra space in `dfSummary()` with time objects
- Allowed one more value for frequency counts in `dfSummary()` when
_"[1 other value]"_ was displayed; this actual value is now displayed instead

- Introduced global options with `st_options()`
- New logical options for `freq()`: 'totals' and 'display.nas'
- In `descr()`, _Q1_ and _Q3_ were added; also, the order in the 'stats'
argument is now reflected in the output table
- In all functions, argument 'split.table' becomes 'split.tables' as per
changes in the 'pander' package
- Argument 'omit.headings' added to all main functions
- In `dfSummary()`:
+ Number alignment improvements
+ Fixed frequencies not appearing when value 0 was present
+ Fixed arguments 'valid.col' and 'na.col' being unresponsive
+ Fixed warnings when generating graphics columns
+ 'graph.magnif' argument now allows shrinking or enlarging graphs
- For `print()` and `view()`, argument 'html.table.class' is now called
'table.classes' and its usage is simplified (please refer to the
corresponding help files for details
- CSS class 'st-small' can be used to make html tables smaller by slightly
reducing font size and cell padding

- Added support for Date / POSIXt objects in `dfSummary()`
- Improved support for `lapply()` when used with `freq()`
- Fixed performance issue with numerical data having a very large range
- Fixed missing line feeds in `dfSummary()` bar charts

- Fixed issue with all-NA factors in `dfSummary()`
- Fixed issues with graphs in `dfSummary()`
- Added vignettes
- Improved handling of negative column indexing by the parsing function
- Removed accentuated characters from docs

- Introducing graphs in `dfSummary()`
- Added rudimentary support for `lapply()` to be used with `freq()`
- Improved alignment of numbers in both html and ASCII tables
- Cleanup in css and upgrade to Bootstrap 4 beta
- Improved support for `by()` and `with()` with `descr()`, `freq()`,
and `ctable()`

Backward-compatibility Note

In `dfSummary()`, parameter name 'display.labels' has been changed to
'labels.col' for consistency reasons. Also, see Notes for Version 0.6.9 about
the 'file' parameter.

_GitHub-only_ release

- Improved alignment in cells having counts + proportions
- Updated vignette to reflect latest changes and added examples using the
example datasets "exams" and "tobacco"
- `dfSummary()`'s last column now includes counts and percentages for both
valid and missing data
- Internal change: **Roxygen2** is now used to generate documentation