Fixes Window_NameBox visual appearance in Skyborn.
Also nuke the second SceneElement constructor that has been
obsolete since the Tilemap mapViewport rewrite.
Instead of replicating the RGSS Disposable interface in C++
and merely binding it, redefine the 'disposed' state as the
entire core object being deleted (and the binding object's
private pointer being null).
This makes the behavior more accurate in regard to RMXP.
It is now for example possible to subclass disposable classes
and access their 'dispose'/'disposed?' methods without
initializing the base class first (because the internal pointer
is simply null before initialization). Accessing any other
base methods will still raise an exception.
There are some quirks and irregular behavior in RMXP; eg.
most nullable bitmap attributes of disposable classes
(Sprite, Plane etc.) can still be queried afterwards, but
some cannot (Tilemap#tileset), and disposing certain
attributes crashes RMXP entirely (Tilemap#autotiles[n]).
mkxp tries to behave as close possible, but will be more
lenient some circumstances.
To the core, disposed bitmap attributes will look
identically to null, which slightly diverges from RMXP
(where they're treated as still existing, but aren't drawn).
The Disposable interface has been retained containing a
single signal, for the binding to inform core when
objects are disposed (so active attributes can be set to null).
This looks like a pretty major change, but in reality,
80% of it is just renames of types and corresponding
methods.
The config parsing code has been completely replaced
with a boost::program_options based version. This
means that the config file format slightly changed
(checkout the updated README).
I still expect there to be bugs / unforseen events.
Those should be fixed in follow up commits.
Also, finally reverted back to using pkg-config to
locate and link libruby. Yay for less hacks!
The general rule I'm aiming for is to <> include
system wide / installed paths / generally everything
that's outside the git managed source tree (this means
mruby paths too!), and "" include everything else,
ie. local mkxp headers.
The only current exception are the mri headers, which
all have './' at their front as to not clash with
system wide ruby headers. I'm leaving them be for now
until I can come up with a better general solution.
Using "SDL2/SDL_xxx.h" instead of "SDL_xxx.h" caused
the include paths provided by pkg-config to be ignored,
and headers from a standard include path to be used instead.