DRY the default template delimiters name and export it.
Squashed commit of the following:

commit 1812a916f34c9b86f3ab87d7c4bb16c1e458004b
Author: Jimmy Chan <jimmyhchan@gmail.com>
Date:   Wed Dec 4 18:55:14 2013 -0800

    lowercase extension .md in npmignore

Closes gh-1003.
Adding "Built with Grunt" badge.

* Achievement Unlocked!
Bumping version to 0.4.2.

* For some reason this commit never got pushed as part of master to GitHub, and became detached.
* Instead of rebasing master, I'm recreating the commit and re-tagging v0.4.2.
* I'm not republishing v0.4.2 to npm, because changes since 0.4.2 have been released don't affect functionality.
* Whoops!
Bumping version to 0.4.3-0.
--debug option can optionally be Boolean. Closes Gh-983, gh-991.
Generalize cli tests, see gh-983, gh-991.
Work-around for isaacs/npm#3958.

* This should allow the build to pass again.
Fixing comment typo
Merge branch 'work' of https://github.com/yuanyan/grunt into work