NavMesh
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-Fixed NavMesh API
-New NavMesh demo
-Support for animated Particles2D
-Fixes for native video playback on iOS
missing navmesh demo and small fixes
Enable ALSA only for Linux
Include stdlib.h for alloca() on OpenBSD
Include string.h for memset() on OpenBSD
Disable X11 joystick functions also for OpenBSD
Import sources for libao driver (unfinished, based on dummy driver)
Add 'ao' build option
Add ao/ subdir to drivers/SCsub
Use libao driver on X11 platform