Rationale:
1. Now to reset a CVAR to default, the user doesn't need to remember the default value.
2. If a modder wants to reset a CVAR via menu command, they don't need to keep menudef and cvarinfo in sync.
src/common/filesystem/file_ssi.cpp:78:20: warning: comparison of integers of different signs: 'int' and 'uint32_t' (aka 'unsigned int') [-Wsign-compare]
src/common/filesystem/file_ssi.cpp:130:38: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int' [-Wsign-compare]
This allows proper dimensions in the stock menus and should make menu layout for mods a lot easier because coordinates are more predictable than with the clean factors.
The feature is opt-in for custom content. As long as only stock elements are used, the menu will be able to switch between both on its own, but as soon as custom classes or custom elements are used, the virtual size must be declared explicitly, defaulting to clean scaling.
In this mode the clean scaling factors are ignored and content is always scaled to fit the screen as efficently as possible.
For the default summary screens an option was added to use this mode, which is a lot closer to the original look of this screen.
It is not 100% identical because it still factors in the author, if given and long level names that may be broken into multiple lines of text.
The background size wasn't taken into account for the splats and the widescreen check never verified the height of the background image.
It will now unconditionally use the new widescreen expansion mode for everything to reduce problems, use the background's display size for positioning overlays and only in the case of 200 pixel tall images perform widescreen positioning adjustment.
* a few shorter fields were moved into alignment gaps
* the visible angles are now stored as floats. Since these are only used for rendering the loss of precision is negligible, but this shortens AActor by 16 bytes alone.
Sensitivity scaling of both axes is now exposed as a raw factor to the user instead of obscuring it behind an unclear 'prescale' boolean.
This also consolidates the coordinate processing code to prevent such discrepancies as were present here from happening again.
Migration code for old config settings is present so that this change does not affect existing configurations.
Sound stopping was done in the wrong place - this killed the sound before they could be serialized for hub travel.
The sound may only be stopped *after* calling G_DoCompleted.
