Patch for "Panel for Joins in the Graphic Query Builder"

Hi All,

As per my discussion with Dave Page:
- Replace the generic dialog box that the graphical query builder uses when
you right-click a join, and select the join type option. It currently uses
an ugly standard dialog. Create a more compact and purpose built one -
like
the one you get when you add criteria, and click on the 'restricted value'
button.

Modifications and addition are as follows:
* Introduced couple of new classes for handling operations:
+ gqbJoinsPanel - Panel for handling the joins in the tab - container for
criteria, order & columns panels
+ gqbJoinsPopUp - Pop up window, when selecting a column from the
table list,
derived from the gqbColsPopUp
+ gqbGridJoinTable - Table for handling all the joins data. It handles
three
columns Source, Join-Type & Destination
* Added new images gqbAdd.xpm & gqbRemove.xpm
* Renamed wxRestrictionGrid to gqbCustomGrid as we're using the same
Grid for
handling the criteria(s) and join(s) in the gqbCriteriaPanel and
gqbJoinsPanel
respectively.
* Added one operator [] in gqbArrayCollection for accessing the
gqbObject object
directory (replacement/accessibility of the object at particular index
will be
easy and fast).
* Removed the context menu "Set Type" removed for join, as this
operation will be
handled from the joins-panel now onwards.

Regards,
Ashesh Vashi