Includes DB changes you need to log all terminals out during upgrade

Tweaks and fixes

• Print unit details. Listed parts would have wrong franchise printed next to them now fixed.
• Print job card. Would erroneously print a random unit type in bottom right of footer for jobs without a unit. Now fixed.
• Subtle bug with initial v5.1 migration.  v5.1 does alot of General Ledger manipulation, such as recoding floor units from code 1-5100 to 1-5110.  v5.1 carefully verifies GL from v4 to v5 is the same besides designed in changes but there is one thing it wasn't doing. C9's general ledger contains a performance optimisation in that it caches balance tallies on demand on monthly barriers. So when getting current balance it doesn't have to tally every single txn in history of system, it only needs to tally txns since last cache barrier. V5 migrator erroneously did not invalidate/reset the cache. Updating to this version of c9 will trigger a cache reset. This problem can be especially obvious for code 1-5110, but also impacts GST holding codes as these are rationalized in v4 to v5 into a simpler set of GL codes. Impact of this bug is that 5-1100 would be inflated to a much higher valuation on realigning inventory to GL which in turn can impact balance sheet and trading statement. It would in time correct itself if you did any operations that automatically reset the cache (such as posting a historical txn or manipulating an old txn). This update forces a clean update which combined with a refresh sync inventory to GL would align everything correctly.

This version includes some initial, unfinished and non-functional work on migrating to next major v5 version v5.2.  Expectation is this will wrap up in a few weeks.