Create own token marker
Copy TokenMarker for Ruby from PdeKeywords
Remove commented codes
Handle # as a line comment starter

and stop handling '/*' and '//'.
Merge branch 'token-marker'
Add game of life sample
Call PApplet methods from outside of its class using method_missing

(J)Ruby does not support nested class so PApplet methods cannot be called
from outside.
This change solves it using method_missing (and `$app` global variable).
Support CONST missing