Semantic Analyser: undef as warning

Report use of uninitialized variables as warning.
Semantic Analyser: reset before analyze.
Set parent node on add/set child.
Added toString to ReportLog.
Semantic Analyser: Fixed some bugs in the tests.
Semantic Analyser: Bug fixes.
Merge branch 'semantic_analyzer' of github.com:swp-uebersetzerbau-ss13/fuc into semantic_analyzer

Conflicts:
	code/semanticAnalyzer/test/swp_compiler_ss13/fuc/semantic_analyser/M1Tests.java
	code/semanticAnalyzer/test/swp_compiler_ss13/fuc/semantic_analyser/M2Tests.java