merge MMcM:  Correct null contamination for IF.

Merge pull request #1102 from MMcM/sql-layer/if-else
https://github.com/FoundationDB/sql-layer/pull/1102
merge MMcM: Handle Types.BINARY like Types.VARBINARY.

Merge pull request #1103 from MMcM/sql-layer/types-binary-like-varbinary
https://github.com/FoundationDB/sql-layer/pull/1103
Give TClass a method to get the corresponding JDBC type id, just as TInstance can get a DataTypeDescriptor.
Update Direct to use those in place of AkType.