Python syntax highlighting breaks on triple-quotes embedded in a non-triple-quoted string

[Eric Pierce]

The syntax highlighter (syntax.py) does not correctly handle "'''" or '"""', such as those present in the __init__ method of syntax.py itself. This is probably due to match_multiline being called after all other syntax highlighting is done; instead, it may be necessary to change state when inside a "..." or '...' string, such that ''' and """ can be ignored in that context.