Selected color is now .9 alpha so keyed/animated/driven statuses
show through when widget is active. Assign color for overriden state.
Also fix progress bar not visible.
The shortcut labels now use the "Item" theme color. Its contrast for hovered
items is a bit low, but not too bad.
Note that this also changes the color of the little toolbar triangle to be grey
(the same color we use for the keymap label). IMHO that looks better though.
This doesn't update any themes other than the default one.
Part of T54711.
The theme is now stored in generated C code,
which can be extracted from existing user preferences.
This theme can then be used for version patching themes
instead of duplicating values
Note that theme versioning has been removed,
since minor changes from now on won't apply well on top of 2.7x theme.
Theme colors from interface_widgets.c have been removed too.
