Add reload garbage test.
Merge remote branch 'upstream/master' into expand-battery-7
Merge remote branch 'upstream/master' into expand-battery-7
Test runahead is being enforced correctly.
Add runahead reload testing.
Add queue size testing.
Retry testing.
Replaced the pickle reg db with simpler flat files.

Closes #327
Added a script to upgrade old-style reg dbs.
Handle corrupted reg db files.
Merge pull request #761 from arjclark/expand-battery-7

Expand test battery 7
Fixed a reg function name.
Merge pull request #764 from hjoliver/replace-regdb

Replaced the pickle reg db with simpler flat files.