standalone version of git's strbuf api
####API#### Please refer to git's strbuf api:
https://www.kernel.org/pub/software/scm/git/docs/v2.3.4/technical/api-strbuf.html
####Compiling####
$ gcc test.c strbuf.c -o executable
####Reference#### strbuf.h : https://github.com/git/git/blob/master/strbuf.h
strbub.c : https://github.com/git/git/blob/master/strbuf.c
####Attribution#### Code is a copy from https://github.com/sijianwudi/varlib/tree/master/string
All credits where due.