If logging debug, include stack trace even for InvalidOperationException.
Add some logging when cache gets cleaned.
Wrong key was used, so every active connection did a clean for the same new AIS.
This random function does not need to make an evaluation context for prepare time operations.
Don't remember query context in prepared expressions; that can point to a whole bunch of stuff.
Merge branch 'preptime-query-context' into pg-statement-cache
Invalidate old statement caches right away.
merge MMcM: If logging debug, include stack trace even for InvalidOperationException

Merge pull request #1206 from MMcM/sql-layer/pg-debug-error-trace
https://github.com/FoundationDB/sql-layer/pull/1206
merge MMcM: Fix places that remember a query context in a prepared expression

Merge pull request #1207 from MMcM/sql-layer/preptime-query-context
https://github.com/FoundationDB/sql-layer/pull/1207
merge MMcM: Tighten up statement cache handling a little

Merge pull request #1208 from MMcM/sql-layer/pg-statement-cache
https://github.com/FoundationDB/sql-layer/pull/1208