Added support for loading .ogg audio files using a combination of
`SDL_RWFromConstMem()` + `Mix_LoadMUS/WAV_RW()`.

`SDL_RWFromConstMem()` now returns an opaque reference that corresponds
to a Javascript-side object which retains the information passed in.
The same for `SDL_RWFromFile()` but it saves different information.

When `Mix_LoadMUS/WAV_RW()` is called, it now expects a reference to
one of those Javascript-side objects and from it, either uses a
pre-loaded Audio, or reads bytes from the file-system to make one,
or uses the bytes originally passed into `SDL_RWFromConstMem()` to
create one.

Note that with this change you can now simply embed sound files in your
app, you do not need to preload them.
update relooper comment
Updated with kripken's suggestions.
Made sure that `IMG_Load_RW` is also aware that it should receive
`SDL_RWops *` generated from `SDL_RWFromFile()`.
Merge branch 'incoming'
fix test_static_link
Fixes in pread()

The bug occurs when pread() doesn't return 0 when asked to read an
offset beyond its buffer.

This behavior is explicitly documented at:
http://pubs.opengroup.org/onlinepubs/000095399/functions/read.html

> If the starting position is at or after the end-of-file, 0
> shall be returned
fix glGetAttachedShaders
Touched up formatting.
No functional change.
Formatting cleanup.
fix isgraph
 - added lchmod
 - fixed up errno values for mknod
 - split up stat tests into test_stat, test_stat_chmod, test_stat_mknod
do not try another outlining pass if there is not that much left anyhow
recursively outline when the total cost is not too high, and adjust outlining parameters
do a restart in the outliner only if the total cost is not too high
adjust outlining heuristics to fully outline even big functions
allow sp to be modified in outlined code, by changing the model to where outlined code returns sp (which also parallels that we sent it as the single parameter)
use blocks in switch cases in outliner
add more outliner testing
stop trying to outline in outlined code, appears to not be necessary anymore