This gets rid of that awkward STANDARD_PREFIX system in which every
branch of the old 'union control' had to repeat all the generic
fields, and then call sites had to make an arbitrary decision about
which branch to access them through.
That was the best we could do before accepting C99 features in this
code base. But now we have anonymous unions, so we don't need to put
up with that nonsense any more!
'dlgcontrol' is now a struct rather than a union, and the generic
fields common to all control types are ordinary members of the struct,
so you don't have to refer to them as ctrl->generic.foo at all, just
ctrl->foo, which saves verbiage at the point of use.
The extra per-control fields are still held in structures named after
the control type, so you'll still say ctrl->listbox.height or
whatever. But now those structures are themselves members of an
anonymous union field following the generic fields, so those
sub-structures don't have to reiterate all the standard stuff too.
While I'm here, I've promoted 'context2' from an editbox-specific
field to a generic one (it just seems silly _not_ to allow any control
to have two context fields if it needs it). Also, I had to rename the
boolean field 'tabdelay' to avoid it clashing with the subsidiary
structure field 'tabdelay', now that the former isn't generic.tabdelay
any more.
I'm about to change my mind about whether its top-level nature is
struct or union, and rather than change the key word 'union' to
'struct' at every point of use, it's nicer to just get rid of the
keyword completely. So it has a shiny new name.
Correcting a source file name in the docs just now reminded me that
I've seen a lot of outdated source file names elsewhere in the code,
due to all the reorganisation since we moved to cmake. Here's a giant
pass of trying to make them all accurate again.
This gets rid of all those annoying 'win', 'ux' and 'gtk' prefixes
which made filenames annoying to type and to tab-complete. Also, as
with my other recent renaming sprees, I've taken the opportunity to
expand and clarify some of the names so that they're not such cryptic
abbreviations.
