Yield after every sendfile() call, do not eait for EINTR/EAGAIN
Use the actual SCHED_IDLE define instead of hardcoding it
Do not call read() again to obtain the request unless needed
I/O wrappers won't return an error value (they'll kill the coroutine)
Processing requests and sending responses don't need to be boolean functions

Error conditions are now handled by the I/O wrappers.
Move call to _url_decode() to _parse_http_request()
Remove unused itworks.png file
Remove unused variables in config:parse_line()
Add license header to lwan-private.h
Parse byte ranges as unsigned ints rather than ints
Simplify _read_request() a little bit by not having nested loops