fixed unexpected end-of-file found error
Merge branch 'master' of https://github.com/dan-hill/postfix.git
group opperator pair validation function added
grouping opperator sequence function completed
case ( in validation complete
added cases to check char following group opperators for validity
strip spaces function added
validation functions complete
imporved encapsulatoin, broke calculation
fixed calcuation for postix expressions
Merge pull request #4 from dan-hill/validate-inflix-string

Validate infix string functionality added and some re-factoring and encapsulation fixes in the postfix class.