Add multi-folder mode
- Add option to enable multi-folder mode (append folders)
- Add option to clear sidebar folders
[multi] Allow quick removal of window folder
- Add menu options to quickly remove single folder in multi-folder mode
Refer to "Items" as "History" in menu
Respect multi-mode when manually loading folder
Manage frequency of menu update

- Ensure menu generation only happens when needed
- Ensure menu generation occurs when switching windows
Handle menu file write err gracefully
Ensure plugin is working with absolute paths
Remove current open folders from menu

-Remove current open folders from menu (way too cluttered)
- Send current window to folder append to ensure proper relative
conversion
Refactor sidebar folder remove

- Simplify folder removal (no more index removal)
- Prompt user to protect against accidental clicking
Limit history items

- Limit history items to 66 just like it used to be
- Expose limit in settings file
Audit folder list for dead links
Menu rework per tito's request
- Rename and reorder menu items
- Remove history clear entry
- Bury append items under submenu
- Add swap setting to swap load and append bury
- Update menu when history limit or swap preference change
- Remove multi-folder mode
Audit folder on load
- Sublime already prevents folders from loading if they don't exist
- But now users will be prompted to remove the folder from history if they choose
Call save instead of save_folders in audit
- A little clean up
Remove obsolete code line
Menu is not generated at startup, when upgrading
Merge pull request #1 from titoBouzout/master

Menu is not generated at startup, when upgrading
Merge pull request #2 from facelessuser/master

Various Enhancements