Very minor syntax adjustments
Fix infinite recursion when reloading module

The monkeypatching for ST3 would cause an infinite loop when reloading
the module (e.g. when saving). Also fix invalid path resolving at load
time because parameter default values are evaluated at parse time
(somewhat).
Wrap the contents of !CDATA instead of the whole

Also assures that trailing newlines in files will always lead to the
same sane.sublime-snippet, because these don't matter anyway.
Use the `with` statement in a bunch of places
Use tabs for newly created sane snippets

They are translated to spaces by ST when necessary, but not the other
way around (afaik).
Revert `with` usage for StringIO()

It's not supported in ST2 :(
Fix Package name detection in ST3
Merge pull request #7 from FichteFoll/various_fixes2

Various fixes