Added a timeout option
Immediately returning when the extension of the file is not supported.
Little more robust PhantomJS script.
Merge pull request #9 from alanshaw/master

Depend on phantomjs module so not have to install phantom separately
Note that imagemagick must be installed to run tests
Merge pull request #10 from simong/master

Added a timeout option
version 0.3.0
Merge remote-tracking branch 'remotes/upstream/master' into screenshot-onCallback

Conflicts:
	README.md
	lib/webshot.js