TextMate Preferences: Refactor Syntax

[deathaxe]

Fixes #377

This PR ...

1. completely refactors/rewrites Property List and TextMate Preferences syntax
   • switch to sublime-syntax v2
   • inherit TextMate Preferences from Property List
   • introduce a common scheme of context structure for all kinds of tags for consistent behavior
   • adds a bailout to not escalate illegal highlighting beyound array/dict boundaries.
2. adjusts completions/snippet selectors
3. fixes broken and cleans up obsolete completion/snippet selectors
4. adds some completions/snippets
5. fixes Goto Symbol for various symbols

Note: Majority of scopes is kept unchanged or tweaked only a little bit as many packages/color schemes seem to rely on them.