* Remove dependency on SDL.h where possible
* Use run-time linking where possible
* Support both SDL 1.2 and SDL 2
* Add device enumeration when using SDL 2
The Emscripten build currently uses SDL 1.2 because it avoids the need
for "-s USE_SDL=2" when compiling. This may change later if there's
ever a need or if there's enough demand.
Rationale:
1) It allows the callbacks to be set at initialization time which feels
a bit more intuitive to me.
2) It avoids the need to call mal_device_set_send_callback(), etc.
3) It's a bit more consistent with the onLog callback. Previously,
onLog would be passed to mal_device_init(), whereas onSend, etc were
set with mal_device_set_send_callback(), etc. which feels needlessly
inconsistent.
Rationale:
1) The number of parameters is just getting too much.
2) It makes it a bit easier to add new configuration properties in the
future. In particular, there's a chance there will be support added
for backend-specific properties.
David Reid
r-lyeh
r-lyeh