Preliminary work towards the new construct class. Lots more little fixes required
but search now works and the tree and schema views are functional.
* as described in #3117 (construct display) and #3131 (Gene page changes)
* The Transgene, Construct and Gene Reports (and probably others) will need some TLC.
Allows override shared template, if one exists template/classes/CLASS/
fix broken overview and expression widgets for Transgene and construct #3117
include Used_for in Construct overview #3131
temp fix for broken phenotype widget due to Drives_transgene and Transgene_product #3131
fix Drives Transgene and Transgene product table by getting data from Constructs #3131
Also fixed bugs with Construct used_for table
Merge branch '245_general_fixes' into staging
Merge remote-tracking branch 'origin/staging' into staging