Reduce and simplify the UI export interface. Having to export functions
with designated names was a bit silly for this case, it makes more sense
for inputs/outputs/etc because they have more functions associated with
them, but in this case the callback can be retrieved simply through the
enumeration exports. Makes it a bit easier and a little less awkward
for this situation.
Also, changed the exports and names to be a bit more consistent,
labelling them both as either "modal" or "modeless", and changed the UI
function calls to obs_exec_ui and obs_create_ui to imply modal/modeless
functionality a bit more.
I realized that I had intended modeless UI to be usable by plugins, but
it had been pointed out to me that modeless really needs to return a
pointer/handle to the user interface object that was created.
Add the ability to be able to call and use toolkit-specific or
program-specific user interface in modules.
User interface code can be either bundled with the module, or 'split'
out in to separate libraries (recommended).
There are three reasons why splitting is recommended:
1.) It allows plugins to be able to create custom user interface for
each toolkit if desired.
2.) Often, UI will be programmed in one language (the language of the
toolkit), and core logic may be programmed in another. This
allows plugins to keep the languages separated if necessary.
3.) It prevents direct linkage of UI toolkits libraries with core
module logic.
Splitting is not required, though is recommended if you want your plugin
to be more flexible with other user interface toolkits or programs.
Will implement a generic properties lookup next, which will be used for
automatic UI handling so that plugin UI isn't necessarily required.
I'm doing this because I might create another data structure called
obs_data for a different purpose. That and obs_program_data feels a bit
less vague for what it does.
jp9000