ENG-4959: add IndexCounter support for SELECT COUNT(*) FROM T WHERE C1 = ? AND C2 > / >= ? when a tree index is built on (C1, C2)
Merge branch 'master' into ENG-4959
ENG-4959: examine last filter and add to endKey; add some test cases.
ENG-4959: remove code not in use and unnecessary import.
ENG-4959: refactor variable "needPadding", add some test cases.
Merge branch 'master' into ENG-4959

Conflicts:
	src/frontend/org/voltdb/plannodes/IndexCountPlanNode.java
ENG-4959: fix index size and minor changes based on Paul's feedback.
Merge branch 'ENG-4977' into ENG-4959

Conflicts:
	src/frontend/org/voltdb/plannodes/IndexCountPlanNode.java
ENG-4959: undo the changes to the plannertest in this branch. Will create a new branch and add more queries.
Merge pull request #643 from VoltDB/ENG-4959

Eng 4959