strcut error handling implemented
streq removed (not used anymore)
remove CodeOptimization

The CodeOptimization does nothing. I removed the dead code from all projects
parts.
Variables and symbol table are now working local. #138 and #124.
Added a copy_symbol_table function
Corrected typo
adjusted integration tests to work with issue #174
changed order for div and sub operators, #174
some new string contants to represent stack element type
added type function
add type function #44, #167
Merge branch 'intertarget-code' of github.com:SWP-Ubau-SoSe2014-Haskell/SWPSoSe14 into intertarget-code