Added Update Function

-update added to spacefunctions...currently a php file that updates the
sql database based on the live data feed url given to us by u of t IT
-update function adds to population table based on apns that are listed
in the buildings table; inserts entries with timestamp given by live
data feed; deletes entries that are older than 2 weeks in the database
-batch file calls update function (can be executed as a windows
scheduled task) ... equivalently can use cron in unix or mac
-spaceFunctions updated to depend on time now...ie populations are only
returned if they were updated within the past five minutes
-found population zero bug in findBusyness: minor test edits