major rewrite

- prevents ppackage control on ST3 from installing package as archive (needed to execute scripts)
- simplify code structure
- better error handling
- fixes known bug with 2 buffers (when run_on_save and save_on_focus_lost set)
- documentation improvements
- put html_erb_patters in settings file explicitly

tested on osx ST2 and ST3 with manually cloned package.