[chirp_users] New Daily Build

[Build System]

Greetings,

A new daily build of CHIRP is available.  This includes changes made
directly to the tree yesterday, and may include additional features,
bug fixes, and/or bugs.  If you are interested in trying it, grab it
from the following location:

  http://trac.chirp.danplanet.com/chirp_daily/daily-20180809


A list of the changes included in this build (since the last daily)
follows:

Changes for Build #532
[Dan Smith <dsmith at danplanet.com>] Fix some style regressions that snuck in

Related to #5997 and #3425

[Dan Smith <dsmith at danplanet.com>] Add mock to the unit test environment

Fixes the tests for #5995

[Dan Smith <dsmith at danplanet.com>] Add metadata blob trailer transparently to image files

This makes FileBackedRadio transparently save image files with an extra
blob of metadata tacked onto the end of the file. The metadata region
begins with a magic string followed by a base64-encoded json blob. I
figure we can call all images created up until now "version zero" format,
since they really aren't formatted at all. Any major format changes after
this can increment the counter in the magic (although it's unlikely we
would need to).

The metadata currently saved includes the radio model details and the class
used at the time the file was created. All existing images will still load,
but when they are saved, will be augmented with metadata. Note that this will
mean images saved from newer versions of chirp will not be readable by older
versions which will be confused by the metadata.

One major feature this brings is the ability to make radio aliases (and other
weak subclasses) be "sticky" across save/load cycles. Right now if you download
with an alias (such as the Arcshell AR-6 alias of the BF-888), the file will
be detected and reported as a BF-888 from that point forward. With metadata in
the image, we can properly select the alias on load to provide better UX.

This includes some low-effort tweaking of the directory and clone code to
select the right radio class based on metadata if present, and to properly
return a radio class for the alias, if one matches. We might want to re-structure
the alias class arrangement after this to make them properly-registered and
fully-functional subclasses so that the hacky DynamicRadioAlias subclassing
done here isn't necessary.

Also note that the generic saving code will not append metadata for filenames
not ending in .img, to preserve behavor for .vx5 files, etc. If a filename forces
a non-standard file extension, the metadata will not be added and the result
will be effectively the same as the older format (which then may not be loaded
properly if it is mis-detected as a different model).

Closes #5995

[Dan Smith <dsmith at danplanet.com>] Add some convenience features to the module loader:

- Mark the background of the main window red once a module has been loaded
- Allow loading a module from the command line for easier testing
- Allow a .mod suffix

#5997