Fix cmake app package issue

Currently the Info.plist file names the app package as OBS.app and cmake
is trying to use 'OBS Studio.app'.  I renamed it to OBS for the time
being just because we don't currently have actual studio interface yet.
Rename cpack description summary (also fix typo)
Fix scene editing for device pixel ratios ≠ 1

Fixes #177
Localization correction for image plugin

Closes #181
mac-avcapture: Remove debug code
libobs/media-io: Handle VIDEO_CS_DEFAULT in video_format_get_parameters
Some minor code refactoring in v4l2 plugin

Small code changes to decrease indentation a little.
Fix a possibly left open file descriptor in v4l2 plugin
Use macro for prefixing log messages in v4l2 plugin
Add more logging to v4l2 plugin.

This adds some mostly user focused logging statements.
Add fallback sizes and framerates to v4l2 plugin.

Until a proper fix is found to support devices that use stepwise
or continuous values for framesize and framerate this adds fixed
values that can be selected.
For devices that support discrete values those are still queried
and used.
Use default color space in v4l2 plugin