Added asin/acos/atan as synonyms for arc--- funcs
Added a '-r' option to show only the result w/o '='
This option is designed for use in shell scripting, etc.
Added an exp(x) function (e^x)
Fixed a bug where abs(x) would convert to integer
Ignored some unnecessary files
Merge branch 'master' of https://github.com/flarn2006/calculator