Add parsing by Unicode character class

Change-Id: I48637a10a1afaaefac9728ef6ae87449a855a305
Fix bugs in selecting the right alternate

Change-Id: Ic55426a816e0e6114dc6ae8975bf1fda24f2d067
Don't generate base rule when requested

Change-Id: Ib06d0cfa89a114841b75a466c9d7c9ead128217f
Generate expression alternates from levels

Change-Id: I9ed246852f2c99b6cc88992dee3b7e6404c49f84
Create expression for CLR function invocation

Change-Id: I8b46aa84bc8acd33f5e982eb57e2914997dcfc07