* remove refs to fmt_tab_width and fmt_tab_indent. support was dropped for them
* move the fmt_cmd and fmt_enabled settings into cfg.py
* use relative imports for the modules in the gosubl directory
* sort the imports
* move the shell setting into cfg.py
* move the autocomplete_snippets, default_snippets and snippets settings to cfg.py
* remove the setting fmt_enabled
* add new setting fmt_on_save to control whether or not to fmt in the save event
* the fmt commands can no longer be disabled, so one can disable fmt_on_save but still fmt the file manually