Syntax Definition fixes

Since I just committed this: SublimeText/AAAPackageDev@215354089dcc7658cc5fbc2200030b8d9944e1d1 I thought I could just as well look at this one too. Turned out that the recursive (nested) complex patterns didn't work so I fixed them by moving the actual "snippet" part into a repository item because `$self` would include the whole file which obviously wouldn't match.

There are still more features in the linked commit but I didn't really bother enough to rewrite your syntax completely. If you wonder how I can edit syntax files in YAML, check SublimeText/AAAPackageDev#13.