cleaned compiler class
Merge branch 'master' of https://github.com/liricooli/Compi

# By sveta
# Via sveta
* 'master' of https://github.com/liricooli/Compi:
  added SemanticVisitor interface to support visitor who throws SemanticError exception
  created TypeCheckVisitor
  change the table type keys to type names

Conflicts:
	src/IC/Compiler.java
basic classes, methods and fields and formals scopes
Merge branch 'master' of https://github.com/liricooli/Compi

# By sveta
# Via sveta
* 'master' of https://github.com/liricooli/Compi:
  implemented type check for plus
  implemented type check for literals
implemented scope visitor and added the printing
better printing of the symbol tables
Merge branch 'master' of https://github.com/liricooli/Compi

# By sveta
# Via sveta
* 'master' of https://github.com/liricooli/Compi:
  added logical bynops
  added type check for mathbynop
Override ToString in Method, included new code to execute in main