Parser supports function definitions without default parameters. No param functions are to be tested yet.
Parser support for default parameter values with tests
Parser support for tuples
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/ru/spbau/jirkov/tralalang/AST.scala
	src/ru/spbau/jirkov/tralalang/ParserTests.scala
	src/ru/spbau/jirkov/tralalang/TralaParser.scala