Fixes bug 938410 - Fixed example in signature_history documentation.
(no bug, doc only) Fixed anchors in the middleware documentation.

Conflicts:
	docs/middleware.rst
Merge pull request #1673 from AdrianGaudebert/938410-sig-hist-doc

Fixes bug 938410 - Fixed example in signature_history documentation.
Bug 939141 - Annotate the largest free VM block in the processed crash.
Merge pull request #1677 from lonnen/largest_free_vm_block

Bug 939141 - Annotate the largest free VM block in the processed crash. r=ted
fixes bug 932064 - Add duration of jobs to crontabber_log table
more lenient duration test
using INTERVAL instead of NUMERIC