Limits/Offsets in Stacky API

Most Stacky API calls now have limit/offset query arguments.
The default limit is 50 and the hard limit is 1000.
Filter on when field for events in StackyAPI
now service is sent in parameters for stacky urls
Merge pull request #181 from manalilatkar/stacky_url_bugfix

now service is sent in parameters for stacky urls
Adding child verifiers to process list
Merge pull request #182 from ramielrowe/master

Adding child verifiers to process list
store image_type from nova notifications
Merge pull request #187 from TMaddox/upstream-stable-4

store image_type from nova notifications
Made owner in ImageUsage and ImageExists nullable since it is possible for the Glance image to have no owner specified.
Merge pull request #188 from anujm/RM2014

Made owner in ImageUsage and ImageExists nullable
Accounting for reconciled old launches in nova audit report
Merge branch 'master' of git://github.com/rackerlabs/stacktach into stacky_refactor2

Conflicts:
	stacktach/stacky_server.py
Merge pull request #160 from ramielrowe/stacky_refactor2

Limits/Offsets and When Filter in Stacky API
Merge pull request #189 from ramielrowe/old_recs_audit_report

Accounting for reconciled old launches in nova audit report