In CegoAction, make the following distribution ready
- show systemspace
- check index
- create, list set, drop counter
Manage append mode also for distributed queries
Idea : With session request append mode is set up
    
- user management with new role concept should be adapted for distributed mode
- serial protocol must be adapted for distributed mode

- Tableset import : allow tableset a to be imported as tableset b ( different names ) 

- improve query execution plans ( e.g. subqueries ) 

- expand system tables to show more information abuout keys, add information for checks
     
- 26.04.2015 : Think about index columns to adress column oriented table requirements
Instead of column based table structure, index columns are addd to a row oriented table
as additional columns. For the addintional columns, AVL or btree index structures are used.
There still seems some referencing issues with this design ...

- Code cleanup : Improve debug messages, more comments for tricky algorithm in code ...
