Fix Modify button

Press "Modify" button second time will cause an error
Name consistency, vlan-id -> vlan
Add tos-bits field for every flow
Merge pull request #17 from starbops/dev

Add tos-bits field for every flow
Merge remote-tracking branch 'upstream/dev' into flowmod

Conflicts:
	core/core.py
	**Notice: we lose flowmod function now :(
Flow modification using CORS

- Add /flowmod REST service (method = POST)
- Modify function: sendJSONP (GET) -> sendFlow (POST)
- Remove useless input tags
The type of data expected from the server is "json".
Capabilities of showing and modifying multiple actions at the same time, separated
by comma
merge from starbops/flowmod