wxgui file import wizards: all files should be defined as '*', not '*.*'

[mlennert]

The wxgui file import wizards define all files as '*.*' which means that if you have total legal tif files which do not have the .tif extension you cannot see them in the file selector.

In r.in.gdal this was replaced by '*' a long time ago, but in the import wizards it is still a nuisance.

Classifying this as a bug since for some users this means they don't know how to import these files.

[annakrat]

Should be fixed in r62813 and backported.