Add Hope markdown parser, and refactoring.
Update jquery v1.11.1, bootstrap v3.1.1.
Update requirements and add usage help.
Merge with github.

* 'master' of https://github.com/galeo/pagedown-editor-only:
  yet another meta.so -> meta.se update
  prevent ESC key from bubbling outwards when used to close modals (http://meta.stackoverflow.com/q/204787)
  another meta.so -> meta.se link update
  better Ctrl-L behavior that doesn't mangle encoded special characters (http://meta.stackoverflow.com/q/258611)