Bug 545811 - [Segments] Add segment based generation of tables'
column DMRs

* Added handler to generate segment based table column DMRs with or
without sub class selection by the user. The generated DMRs are added to
the multi segment.
* Added unit tests for the generation
* Register handlers and only show their context menu entries if segment
mode is enabled
* Only show old handlers if the segment mode is disabled

Change-Id: I71a74cd56a287c7e6534890f046b1b4d719bf008
Signed-off-by: Lucas Koehler <lkoehler@eclipsesource.com>
12 files changed