Mofification after the merged version
testSort is ok.
doing test sort.
Fixed the bug caused by improper implementation of < operator in
data_type.
Before merging with scdong's codes
Merge branch 'scdong'
Fixed the bugs after merging. This is a relatively stable version.
ignore files
sort bug found!
a bug fixed in Single Column Scan
Merge branch 'casa'

Conflicts:
	.cproject
	.gitignore
	BlockStreamIterator/BlockStreamPrint.cpp
	Test/TestMain.cpp
	ids.h
ignore
ignore
before fetch li's branch