Make previous/next completion shortcuts use fuzzy scoring (fix #36)

- sort items before calling the original _selectNextPreviousByPriority
- also make the sort preserve alphabetic order for equal scores
Faster filtering with prefix anchor

also added forgotten line to actually cache the results
Use a stack with cached results for faster backspacing (fix #29)
Remove (now redundant) prefix- and letter- caches.
Bugfix: inline preview sometimes shows despite being disabled

- when bringing back completions another time
Bugfix: completions not showing for just one letter (fix #37)

- removed some not needed and wrong legacy code
Move FuzzyAutocomplete menu item to Editor submenu
Add an option to enable/disable the plugin in the settings.
Bugfix: alphabetical list was not really sorted if using multiple workers

... each worker segment was, but segments order was arbitrary

also tweaked reduce phase and finding selection
Don't show all the options when plugin is disabled.

also fix some misaligned text
Bump Version to 2.0.1; Update Readme and Changelog
Bugfix: don't modify rowHeight if delta or stored value is 0

Xcode was complaining when setting to 0

Xcode[66942]: ERROR: Negative values for setRowHeight: not allowed (0.000)
Merge branch 'develop'; Version 2.0.1