Demo cleanup
Refactored demo build scripts
Demo: permalink, autoprefixer
Demo: added options support
Demo: set text area & ouput boxes to full height
Fix: whitespace in links element can contain newlines
Fix: "\*" isn't a part of a emphasis marker sequence
Workaround for a bug with nested list elements tightness
Update tests
Demo: updated css & browser js files
Updated demo text style
Add tokenizeSingle method
Add single-rule test cases
Add state.level everywhere