Adding oozie files to control addition and deletion of webrequest table partitions

util/hive/partition files are generic enough to be used with any external hive table.
webrequest/partition coordinators actually schedule the hive partition workflows
that add and drop partitions.

Note that this is intended to be used with a different table setup than we
currently have in Hive.  I intend to merge the 4 webrequest_* tables
into a single webrequest table, each with a partition for the particular
webrequest_source.  Data after camus imports will look like:

  webrequest/webrequest_<source>/hourly/<year>/<month>/<day>/<hour>

The webrequest table will then contain 5 partitions, 4 for the
date and one for the webrequest_source (e.g. text, bits, mobile, etc.).

Change-Id: I7d658b431c103eb8f73afac136369d401a3958ba