Delete MTs and most supporting code
Remove (now unused) ScanHook from BasicDMLFunctions
Lookup directly by index ID
Varargs instead of explicit array
Minor cleanup and more QP helpers on ITBase
Re-add a cleaned up and consolidated TimePoint/TimeMarker
Builder for new concurrent, coordinated tests
Helper for defensively starting, joining test Threads
New MT for isolated DML
merge nathanlws: Start over with MT style tests

Merge pull request #1080 from nathanlws/sql-layer/remove-and-replace-mts
https://github.com/FoundationDB/sql-layer/pull/1080
Add system SQL/J jars, just like system routines.
Ignore plugins.
In tests, too.
merge MMcM:  Add system SQL/J jars, just like system routines.

Merge pull request #1081 from MMcM/sql-layer/system-sql-j-jar
https://github.com/FoundationDB/sql-layer/pull/1081
Give at least one of the allowed arities instead of -1.
Consolidate, standardize and extend the CURRVAL & NEXTVAL functions.
More YAML tests.
Correct error message.
merge MMcM:  Consolidate, standardize and extend the CURRVAL & NEXTVAL functions.

Merge pull request #1082 from MMcM/sql-layer/currval-one-arg
https://github.com/FoundationDB/sql-layer/pull/1082