Re #27: Add auto-generated lexer
Re #27: Merge branch
Merge branch 'DelvarWorld-i-cant-even'
#27, #28: Push negative constant recognition in lexer to grammar/generator stage, fix unary generation bugs
#3: Add preprocessor directives module with basic define/undef support
Remove logging statements
Adding module export statement to expose glsl
Adding mocha tests
Expose preprocessor directives to the world
Preprocessing extension statements and exposing them to the world

Addresses issue #30
Merge branches 'strutz', 'array-subexp', 'ackrc' and 'preprocessor-updates' into bleeding-edge