[gnome-db] Mergeant CVS

["Vivien" <malerba gnome-db org>]

Hi!

I've commited the latest improvements I had for libgdasql, libmergeant and
mergeant (HEAD). Mergeant is now fairly useable with PostgreSQL, and needs
to be tested with other providers.

At the moment the following features are implemented:
- database table's browsing and content editing
- data types browsing and lists of functions using any data type
- custom query creation from SQL statement for SELECT, UPDATE, INSERT and
DELETE queries (no sub query parsing yet).
- for custom queries, it is possible to execute them and they may have
some values considered as variables (using a specific SQL extension, see
libmergeant's doc about SQL queries).
- up to date documentation for libmergeant.

Here is a short MUST HAVE list before a 1.0 can be rolled out:
- user documentation
- visual representation of database constraints
- point and click query editor and creation druid
- a SQL console
- general UI improvements
- testing, testing and testing...

Please test it and report bugs, ideas, critics, etc

Cheers,

Vivien