Add abacist module & role; provision on stat1001

'abacist' is a simple web analytics framework that I am currently developing
with the Analytics team. It keeps per-URL page view counts in redis. Counts are
stored at different time resolutions and automatically rotated, like a
round-robin database.

Change-Id: If2fc7b517780edf0627beb5e84b141da5c67d9bb