Clarify javadoc
Add RowType to exception message
Test helper for checking index contents
Failing ALTER affecting GI case
Restrict GIs being maintained to ones the table participates in
Failing test for when there are both dropped and affected GI
Use new version of table for second affected drop
merge nathanlws: Small ALTER affecting GI fixes

Merge pull request #1026 from nathanlws/sql-layer/tighten-alter-gi-building
https://github.com/FoundationDB/sql-layer/pull/1026