TAJO-39 Remove the unused package tajo.engine.plan.global and all files inside the directory.
Revert "TAJO-39 Remove the unused package tajo.engine.plan.global and all files inside the directory."

This reverts commit 64d581f81a6f541401a1d811008a1fe1051d5fc6.
TAJO-39 Remove the unused package tajo.engine.plan.global and all files inside the directory.
Modify CHANGES.txt to record TAJO-39.