refine for bug #241, increase the small bytes for merged read.
for bug #248, use simple buffer for hls.
for bug #248, use simple buffer for http.
for bug #248, rename SrsBuffer to SrsFastBuffer.
fix #248, improve about 15% performance for fast buffer. 2.0.49
update readme
add performance header to control options for performance. 2.0.50
for bug #194, add the send macro to performance.
for bug #241 and #248, improve about 25% performance. 2.0.50
update readme
fix #249, cache the chunk headers info to +5% or +10% performance. 2.0.51
update readme.
for bug #241, simplify the merged read config macros.
for bug #241, simplify the buffer, donot reset when chunk size change.
for bug#241, simplify the buffer, donot change its size.
for bug#241, simplify the buffer, donot realloc it.
for bug #249, simplify the macro, 0 to disable chunk stream cache.
for bug #241, support mr(merged-read) config and reload. 2.0.52.
fix bug for bug #241, default to 32k for socket buffer.
update performance to 4k, when mr_sleep to 2000ms. 2.0.52