Config is now more powerful!
The socket fd close bug is fixed now! -_-
hashtable now has two models: with mother page and without mother page
Fixed bug caused by early exit of Environment.
The memory leak in join is not fixed. The lock array in hash table may
be the underlying reason for memory leak. This commit is submitted
before I try to fix the problem of lock array in hashtable.
Before seeking help from scdong
All the unnecessary source files are removed.
Fixed memory leak caused by too frequently memory allocaton and free of
small size.
Remove unnecessary files and add gtest
Last commit is not complete.
Reorganized the code structure.
re-organized code structure
Merge remote-tracking branch 'origin/master'

Conflicts:
	AdaptiveEndPoint.cpp
	IndexManager/LogicalCSBIndexBuilding.h
	LogicalQueryPlan/EqualJoin.cpp
	LogicalQueryPlan/Scan.h
	Message.h
	Test/TestMain.cpp
	Test/TestSuit/hash_table_test.h
	Test/TestSuit/in_segment_scalability_test.cpp
	Test/test_iterator.cpp
	Test/test_scdong.cpp
	hashtable.cpp
	hashtable.h
	storage/MemoryStore.h
	utility/synch.h
Removed unnecessary files.
Performance Monitors are moved into BlockStreamIterator folder.
Code reorganization:
1. Block/* are moved into common/
2. Serialization/* are moved into BlockStreamIterator/Serialization/
Tuple-at-a-time iterator base is removed.
'Limit' is currently supported! -_-
The start index in limit cause not starts from 0.
Add PerformanceInfo in expander status.