Miss-hit

* Minor fix for the case where an excluded_dir contains a broken
config file.

* 151 Rewrote configuration file mechanism. The change is backwards
compatible, so existing files will continue to work.
* Fixed an issue where broken configuration files higher up the
directory tree (and unrelated to the project you're analysing)
impacted analysis.
* Fixed an issue where files in directories hard-excluded (i.e. using
`exclude_dir` as opposed to `enable: 0`) counted as files excluded
from analysis. This seems weird, but the intention was that excluded
directories were effectively considered deleted and would not influence
anything, ever.
* We no longer enter any directory starting with `.` when searching for
files to analyse.
* New config directive `project_root` that effectively resets all
configuration and starts from a blank slate.
* Any directory containing the `.git` directory is also considered a project
root. This means checkout out sub-projects are not influenced by your
configuration file. I plan to make this behaviour configurable in the
future.
* Proper [documentation for configuration files](https://florianschanda.github.io/miss_hit/configuration.html)

* 148 MISS_HIT is now a PyPI package. This change should also make
it much easier to re-use the compiler framework of MISS_HIT in other
tools. You can still use it by just checking out the code, but be
aware that some entry points have changed:
* most source code lives in the miss_hit package (not the top-level)
* the top-level script `mh_metric.py` is now called `mh_metric`
* the top-level script `mh_style.py` is now called `mh_style`

* Reworked Simulink parser to provide a much deeper parsing. While
there is no user-visible effect of this change right now, it paves
the way for producing code metrics on the Simulink model itself (and
not just embedded MATLAB code).

* MH Style can now analyse (and fix) code inside Simulink models. This
new functionality must be enabled with the new command-line flag
`--process-slx`. This flag is temporary and will be removed in the
future once this feature is stable enough.

* MH Style has a new configuration option `copyright_in_embedded_code`
which is turned off by default. By default the `copyright_notice`
rule does not apply to embedded code, and this option can be used to
control that behaviour.

* MH Style has a wider definition of a `useless_continuation`. This
rule now also applies to continuations that begin statements.

* MH Metric has a new syntax in configuration files to completely
disable a named software metric. You do this with `disable` for a
named metric, e.g. `metric "function_length": disable`. With this
option the metric doesn't even appear in the final report (as
opposed to the default where we measure a metric, but not complain
about it).

* MH Metric has new syntax in configuration files to enable or disable
all metrics. You do this by using `metric *: report` and
`metric *: disable` respectively.

* MH Metric now uses more human readable names for the metrics in both
the HTML and text report.

* Disabled (but not removed) the `implicit_shortcircuit` rule. It
turns out that in some cases `&` really does mean `&`, even inside
an if guard. Curiously, mlint/checkcode shares this bug. To properly
resolve this we need semantic analysis and type inference; so until
then this rule just does nothing.

* MH Metric can now process and produce metrics for code inside modern
SIMULINK models (slx files). This does not work yet in MH Style, but
I plan to also support this there.

Features
* MH Style has a new (autofixed) rule `no_starting_newline` to make
sure files do not start with just whitespace.

* MH Style has a new (autofixed) rule `implicit_shortcircuit` that
complains about misleading use of `&` and `|` inside if/while
guards.

* The MH tools now allow all possible class method names, even the
ones that are highly questionable like "import", "end", or
"arguments".

Fixes
* 131 The parser now allows the end of statement (newline, comma, or
semicolon) after an enumeration keyword to be optional. I.e. we can
now process this code fragment correctly:


enumeration Picasso, Laura, King_Edward
end