Improved parser Performance

[generalpy101]

Main changes were reducing number of splits and directly do byte parsing instead of string parsing. Not a very huge improvement in performance but can see results after change:
eg:
After change

$ redis-benchmark -p 9999 -t SET,GET -q
WARNING: Could not fetch server CONFIG
SET: 14440.43 requests per second, p50=3.247 msec
GET: 14587.89 requests per second, p50=3.247 msec

Before change

$ redis-benchmark -p 9999 -t SET,GET -q
WARNING: Could not fetch server CONFIG
SET: 13415.62 requests per second, p50=3.487 msec
GET: 13956.73 requests per second, p50=3.407 msec