Fix: it is not possible to send special chars (such as '&') as task description

Fixed by adding encoding of the data sent to the server over HTTP
nasty hack which enables to use kanbanik on older versions of mongodb without
the support of elemMatch. It is especially useful on ARM devices where only
older versions of mongodb are ported.
Fix: The loading of the task from legacy mongodb did not return the description
Added the getTasksCommand
After session timed out the upcoming login did not pass
first steps to implement server side events to be pushed to client in real time
Some UI enhancements, namely:
- smaller workflowitem place header
- no header occupied by it if the place is supposed to be headless
Since Shiro does not bind the build subject to the thread context it may from
time to time confuse the sessions.

Fixed by binding the session to the thread context manually.
Changed the design of the main board (unfinished yet)
- the whole task has one color, not only the header
- removed the borders around the workflowitems
- the size of the task depends on the amount of text in the "short description"
continued the implementation of the server push of task related events
Added move task and fixed delete and add task server events
Added a possibility to pick between traditional and new design of the task.
Finished task resize
- Updated web.xml schema to 3.0
- Fixed a class cast exception in the WorkflowitemPlace
Added possibility to filter according to user, class of service, short/long description and id
Added due date to filters
filter cleanup