Changed shell to bash

The script depends on specific bashisms (see issue #1).

Changed the interpreter call to reflect this.
Improvements: case-insensitivity, whitespace

Added two minor improvements to the script.

1. BUGZID string is now case insensitive.
2. Whitespace around the bug number does not lead to errors.

This means that instead of

	BUGIZD:123:Text...

the following case identifier is now also accepted:

	bugzid: 123 : Text...
Changed URL string to work with FogBugz/Stash

Our local installation of FogBugz/Atlassian Stash did not work with
the original script. Adapted the script to function properly.