Provide visual feedback when loading available vector map list
When vector module window is opened there is significant (up to 6 seconds for Spearfish PERMANENT!) delay when opening list of available vector maps and no visual feedback to user that something is still happening. In comparison gis.m displays vector map list instantly. If after first click on vector map list drop-down menu user clicks on something else, list is not displayed. This may lead to wrong conclusions that there are no vector maps or wxgui is completely broken. After drop-down list has been displayed for first time, there is no delay on subsequent displaying.
Windows Vista running WinGRASS-6.4.SVN-r41233-1