MapServer doesn't see uppercase .SHP files on Unix

[dmorissette]

We've had some users report that if they have shapefiles with their extension in 
uppercase (.SHP/.SHX/.DBF) on a Linux server then MapServer won't see them.  
This makes since the .shp extension is not included in the DATA parameter, it is 
added automatically in mapshape.c, and the code in mapshape.c doesn't try to 
handle uppercase extensions.  It is poossible that the same issue exists with 
image file formats as well but I didn't check.

We can either (1) document this problem and tell the users that they should make 
sure their shapefile dataset filename extensions are in lowercase, or (2) modify 
mapshape.c to try a lowercase .shp first, and then try again with .SHP if the 
first one failed.  The second option isn't very hard to implement, we do it all 
the time in OGR drivers, but it adds a little overhead.

What do you think Steve?  Should we fix this or just document the problem?