remove reduntant item
Merge branch 'Client & Server'

Conflicts:
	.gitignore
try to merge the data type codes contributed by dsc
data type promotion
a synchronizing point for zhuhe and kai
+ for arithmetic expression, < for compare expression,
CASE..WHEN..THEN..ELSE for composite function.
test utility
add setValue methods to ExpressionItem to facilite the intialization.
3-8
3-9
3-9 20.31
before fetch li's branch
test
test for push
physical operator for CSB index completed.
Logical CSB index build iterator completed.
Copy before changing the CSBNode class into non-template
Add index manager to maintain the whole set of CSB+ tree indexes.
Includeing the initialize in Environment
update for sql parser:
support create and drop index,drop table and database
check table whether is existed when create table
serialization of catalog