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
Merge pull request #108 from Kha/pipeline

Implement an actual Compiler pipeline, use it to simplify test matchers
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
Merge pull request #109 from jspam/039-even-moar-typer

Finish the typer (almost, haven't checked against the spec yet)
Add tests for operators, field accesses, assignment
Add test for duplicate/wrongly named main methods
Require programs to have a main method
Visit first parameter of array access