fix a bug about expression
changed database design document
added jaxen for dom4j
add two const http method
RELEASED a di framework
add a new field to book model

name
.
optmise imports
some files about layout
refactor some code about business and dao
book and home
add book servlet and mapping
Merge branch 'master' of https://github.com/yanghua/hades

Conflicts:
	src/main/webapp/pages/layout.jsp