Removed unusued import
Changed IR to use the symbol table
Added implementation of boolean operators to the interpreter. General improvements in resolving identifiers
Updates to maso source files
Interpreter now works with current maso source files. Closes #16, #14, #11, #10
Merge branch 'runtime' into develop

Conflicts:
	src/test/java/net/danielobrien/maso/lang/intermediaterepresentation/instructions/MasoInstructionTreeBuilderTest.java