First pass as implementing the greasemonkey API. This patch

First pass as implementing the greasemonkey API.  This patch
includes a javascript file with stubbed versions of all the
greasemoney API methods as well as changes to the Greasemonkey
slave to inject this javascript file along with other user
scripts into the page.I also have a userscript I'm using for
the unit testing of the API methods.  I don't think there is
a good place for it in the chrome tree (if there is I'd like
to know), but you can view it here:
http://skrul.com/greasemonkey/test.user.js

Right now all the tests fail except for testLog and
testUnsafeWindow.