Includes DB changes, you need to log all c9s out during upgrade

Tweaks and fixes

• Added SA sale forms (contract of sale, form 2 + form 4)
• Performance bugfix with customer filter. Some filters can cause c9 to grind to a halt. Some tweaks here which hopefully fix up some pathological cases in database query performance (search for something like kvak0 breaks into two full texts, 'kvak:*' and '0'. '0' will often seqscan because of its huge hitrate which of itself isn't terrible, but in context of original query with tsquery aggregates etc would generate lousey performance, reworked design of query so now alot faster)
• Profit summary bugfix. Spares profit reporting was quite borked and has been for some time probably and would not return much data for spares. Now fixed (query issue with null columns and dealing with invoice sales where invoice lines have not been merged onto another invoice )