Squashed commit of the following:

commit 8f0bca4a9dc18efeb73ded6e17ebc6108564289a
Author: Luke Campagnola <luke.campagnola@gmail.com>
Date:   Mon Jan 13 11:41:56 2014 -0500

    Backward compatibility for generator pulse train 'interpulse_length' parameter
Copied changes from BZR
Corrected Imager merge
Corrected ScanProgramGenerator merge
Fixed improper merge in imager (device names)
Fixed import issues in ScanUtilityFuncs
Merge remote-tracking branch 'acq4/develop' into copy-changes-from-bzr
scanner stuff - still not quite right
Fixes to scanner, Imager and Imaging (task), seems to be working.
Imaging module-parameters changed/renamed for consistentcy, bug in mosaic
editor corrected.