Involves making asserts use printf instead of the log functions (log functions are asynchronous and, as such, the log won't be printed in time)
As such, the log type argument was removed (printf obviously can't use it, and it's made obsolete by the file and line printing)
Also removed some GEKKO cruft.
This prevents a crash when the buffer size returned by the driver is 0,
in which case no space is allocated to store even the NULL byte and
glGetShaderInfoLog errors out.
Thanks to @Relys for the bug report.
Screen contents are now displayed using textured quads. This can be updated to expose an FBO once an OpenGL backend for when Pica rendering is being worked on. That FBO's texture can then be applied to the quads.
Previously, FBO blitting was used in order to display screen contents, which did not work on OS X. The new textured quad approach is less of a compatibility risk.
