"Constant time" symbol table

Actually, it's amortized constant time
Merge pull request #105 from TehMillhouse/const_time_symtab

"Constant time" symbol table
Bugfix: while-statements should not be counted as return statements, as it's not statically checked if their body is entered or not
Merge pull request #106 from Stoeoef/master

Bugfix: while-statements should not be counted as possible return statements
Namer: Don't visit main method parameters
Merge pull request #107 from Kha/namer-main-params

Namer: Don't visit main method parameters
Implement an actual Compiler pipeline, use it to simplify test matchers
Implement --check. Fixes #102
Typecheck == and !=
Typecheck array accesses and make sure the typer descends into everything
Check that the left-hand side of an assignment is a lvalue
Typecheck method calls
Get rid of an isInstanceOf check
Inline a method call
Simplify a Boolean expression
Return type of left hand side as type of assignment operator
Lvalue -> LValue