add the doc which contains some images and documents.
change the image to jpg.
change the image to jpg.
can do a a+b-1, a-b+1 at the physical level.
project and sort.
project logical operator can be done.
project logicalOperator successful!!!
double can't be supported well.
Merge branch 'casa'

Conflicts:
	.cproject
	.project
	Test/TestMain.cpp
	common/ExpressionCalculator.cpp
	common/ExpressionCalculator.h
	common/ExpressionItem.cpp
	common/ExpressionItem.h
	common/Expression_item.cpp
	common/TypeCast.h
	common/functions.h
3-8
Set the default value for the thread count in the construct of Barrier
to be 0.
Add RegisterThread() to Barrier to increase the thread count by 1.
Add setEmpty() to Barrier to reset thread count to 0.
The expected number of expanded threads does not need to be pre-defined
now! This is the first step into the adaptive expander framework.
fixed a minor bug
Reorginized the position of synch.h
Added ExpandedBlockStreamBase, which will provide stardard method for
expandable iterators.
ExpandableBlockStreamProjectionScan has been modified by using the
stardard methods provided by ExpandableBlockStreamIteratoBase. The code
is graceful now~ -_-
ExpandableBlockStreamFilter has been modifed by using the
ExpandableBlockStreamBase stardard methods. To be test the correctness.
Mofification after the merged version
3-9
testSort is ok.