[matchtags addon] Add

Issue #1625
[real-world uses] Add Echoplexus and Shadertoy
[jade mode] Add
[jade mode] Integrate
[tern addon] Support custom type/completion tips

+ a few other fixes
[tern addon] Add crude support for web workers
[tern addon] Add fileFilter option
[tern addon] Add hideDoc method
[jade mode] fixed start of line bug

... that caused certain jade files to cause brackets to hang
[css mode] Fix incorrect entering of propertyValue context

Closes #1533
[css mode] Better fix for #1533
[scss tests] Simplify a test to handle a limit in property parsing
More hacks in character measurement to fix cursor at zero-width widget

Issue #1617
[themes] Fix unrestricted rules
[midnight theme] Remove some rules referring to classes CM does not use
[merge addon] Fix another layout issue