Clarify that grabbing the mouse only works with one window at a time; this was
always true at the system level, though SDL could previously get confused
by multiple simultaneous grabs, so now we explicitly break any existing
grab before starting a new one and document it as such.
Also track the window that is currently grabbed, and provide an API to query
for that window. This makes it easy to automate mouse ungrabbing at
breakpoints with gdb7's scripting, since the scripts can now know which window
to ungrab.
In 2.1, we should probably change this API to SDL_GrabInput(win) and
SDL_UngrabInput(void), or something.
Jonas Kulla
The configure script didn't differentiate between Linux and Android, unconditionally compiling in the unix implementation of SDL_sysfilesystem.c.
I'm probably one of the very few people building SDL for android using classic configure + standalone toolchain, so this has gone undetected all along.
