Foursquare api

[astricks]

Simple foursquare class to work with venues.

[astricks]

I didn't mean to push to master, wanted to generate pull request to a branch on wasted code.

Still to do:

1. Converting the resultset to JSON and then filling in our venue structures to return
   OR
2. Filling in expresso venue objects from the GET response itself and returning expresso venue objects

[astricks]

And i wrote much more than that in two weeks, I just threw more code away than I committed!
Don't lose hope! :D

[isingh]

Since it is already on your branch, its fine if the pull is for master. We can keep adding commits (basically commit locally and then do a git push origin foursquare_api and it will automatically pick up those commits and update this pull request.