update request struct to include stats
fix comment in request.h
add stats for req_arrival, req dispatch, req_read, req_complete
Fix lock up when running with buffer size of 1
output.c: Update spin time to 2
Wait when all workers are busy
Fix SFF regression
Fix a bug that causes all instances of the request struct to all have the same
filename
Merge branch 'master' into server-stats

Conflicts:
	server.c
Implement stat-req-age
Implement thread statistics
Update thread stats before handling request
Fix stat-req-read
Fix stat-req-complete
Put requests in the buffer in order and keep track of last served buffer index
Add README