Make target for obtaining alpha files

[Brian Rice]

Since keeping up to date with the development pace and bootstrapping is 
not trivial, we've added a target to the top-level Makefile called 
"get-alpha" which will grab alpha VM's and images from the Slate 
website. This uses wget, but at the same time may overwrite whatever 
images and sources you have of the same name in your top Slate 
directory, so make sure you always have copies or rename them (perhaps 
we'll add an automation to provide a safe default).

--
Brian T. Rice
LOGOS Research and Development
http://tunes.org/~water/