Suppress a handful of tests not compatible with random
merge nathanlws: Skip somes yamls that are incompatible with random context

Merge pull request #945 from nathanlws/sql-layer/skip-yamls-random-context
https://github.com/FoundationDB/sql-layer/pull/945
Subclass Sorter as to not require always going to file/double writing.
Comment derived class
Bump dependency
Only MergeJoinSorter closes
Set list to null after deleting
merge nathanlws: Subclass Sorter to provide a pull based interface

Merge pull request #947 from nathanlws/sql-layer/pull-based-sorter
https://github.com/FoundationDB/sql-layer/pull/947
Failing test
Manually tack close state
Test name clarity
merge nathanlws: Work around isActive() issue in MergeJoinSorter

Merge pull request #948 from nathanlws/sql-layer/merge-join-sorter-input-workaround
https://github.com/FoundationDB/sql-layer/pull/948