Prevent self snippet from working inside strings

This is to prevent false positives when tabbing within a string, especially when inside another snippet. Fixes #26.
Use Python 3 syntax for Try… snippets

This is compatible with Python 2.6 and higher, more info:

http://www.python.org/dev/peps/pep-3110/#implementation
Avoid Python3 "list.remove(x): x not in list" error

Every time TextMate2 updates (and refreshes this file), I get the following error running in-app with Python3 (Python works fine).

	Error in sitecustomize; set PYTHONVERBOSE for traceback: ValueError: list.remove(x): x not in list

It looks like my sitecustomize is being run twice with Python3 (lines 20-25), which is provoking the error; the `os.environ['TM_BUNDLE_SUPPORT']` is removed the first time, so it gives an error trying to remove it the second.

This problem has also been looked at [here](https://github.com/mxcl/homebrew/pull/16848) and [here](https://github.com/textmate/textmate/issues/812).
Revert "Don’t use stack trace formatter if TM_PYTHON contains ‘3’"

The issue that caused this to be needed has been fixed in e62bab275dd6b942e03f40bf26f88ab73a8e7071. The exception catcher still does not work under Python 3 but it no longer causes an exception itself.
Fix txmt:// column param in pycheckmate

Per [the url scheme](http://blog.macromates.com/2007/the-textmate-url-scheme/).
Remove special scoping of empty strings

We can now accomplish the same with left/right scope matches.
Disable string quote characters inside block strings

This allows manually typing the end of the string without getting four quotes, fixes #29.
Trigger “indent current line” after inserting a colon

Since we have disabled indent-as-you-type for Python, we don’t get the automatic decrease of indent when typing the else keyword in an indented if block.

This commit adds the colon as a special case for triggering automatic indent of the current line. Ideally there would be an option to only partially disable TextMate’s indent-as-you-type so that this macro was not required.
Add squiggly braces as increase/decrease indent characters

Although we have “indent as you type” disabled for Python, we should still strive to have correct indent patterns since we estimate indent after pressing return and (recently) typing a colon.
Revert "Trigger “indent current line” after inserting a colon"

While this works for it's intended purpose (elif/else) it gets triggered in too many other places to be functional. Since we can't currently tell if we are on a line with an elif/else we have to remove this.

This reverts commit ef08362f19f9e361c3ff8725411c910e3d944bcd.
Merge branch 'master' of github.com:textmate/python.tmbundle