add SHA-1 calc func

Signed-off-by: wenpincui <wenpincui224@gmail.com>
database works

Signed-off-by: wenpincui <wenpincui224@gmail.com>
add a little logic for db sha1 map creation

Signed-off-by: wenpincui <wenpincui224@gmail.com>
Merge branch 'master' of https://github.com/elsonLee/Co-Reading

Conflicts:
	Co-Reading/src/com/example/co_reading/painting/PaintingView.java