Start benchmarking different itoa implementation
Implemented faster itoa with bit counting and reverse write
Pass GCC compilation
Add VC itoa perf comparison
Use branchlut implementation for itoa conversion.
Fixes stack overflow
Merge pull request #80 from miloyip/issue31optimizeitoa

Issue31optimizeitoa
Merge remote-tracking branch 'origin/master' into IterativeParseOptimization