- some improvments in styles (app.css)
- group management added
1. add new group functionality
2. add user to group functionality only to ui
3. coresponding tables added to DB
4. model constructed from DB & corresponding controllers
5. ADDGroup servlet Added
- delete station completed
- group management completed
* add station to group functionality completed
* station & connection relationship cascaded
* groupList servlet added -> get list of groups
* stationgroupList servlete added -> get list of stations belong to that group
* all stations now added to default group
* first should create default group (it will be added automatically in the future)
* station lists now categorize in groups
- group management page is Management.html