HSTJ-35: ConstantPropagation implemented (without tests)
HSTJ-35: ConstantPropagation implemented with tests
HSTJ-35: ConstantPropagation implemented with tests
HSTJ-35: Optimizations refactoring
HSTJ-35: Useless variables implemented (without tests)
Bugfix
HSTJ-35: Optimization removed from evaluation
AstOptimizerTest implemented
HSTJ-35: Bugfix for acceptance tests, stage 1 (failures: 1, errors: 23)
HSTJ-35: Bugfix for acceptance tests, stage 2 (failures: 1, errors: 0)
HSTJ-35: Simple optimization statistics added
HSTJ-35: Simplifier implemented
Merge branch 'master' of https://github.com/MegafonWebLab/histone-java
Merge branch 'optimizer'

Conflicts:
	src/test/java/ru/histone/HistonePlaygroundTest.java
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/main/java/ru/histone/evaluator/EvaluatorContext.java
	src/test/java/ru/histone/optimizer/AstOptimizationTest.java
HSTJ-35: Bugfix after merge
HSTJ-35: Bugfix after merge