Support changes to sublime-syntax from Sublime Text `Build 4075`

[jrappen]

Changes from Build 4075

• hidden file extensions
  • hidden_file_extensions
• sublime-syntax v2
  • version: 2
• inheritance
  • extends
• meta patterns:
  • meta_prepend
  • meta_append
• match patterns:
  • pop multiple contexts via pop: 2 etc.
• including an external prototype

Documentation

https://www.sublimetext.com/docs/syntax.html#ver-dev