Add alias parsing function. Add push alias list function
Add unalias function
Merge branch 'master' of github.com:JinSun2014/A_Tiny_Shell into develop-JinSun
Merge Master
Add replaceAlias function
Fix unalias bug
Add ~ interpreter; fix some output;
Fix ~ interpreter; change alias to alphabet order
Merge branch 'develop-JinSun'
implement io redirection
solve merge
modify Makefile and man page