PHP_MAPSCRIPT - shapefileObj->free() does not close file

[dmorissette]

With PHP 4.0.6, a call to shpfile->free() does not close the file immediately, 
and this has the side-effect that a script that creates a temporary shapefile 
cannot reuse it until the next script execution.

This can be reproduced using test_writeshape.phtml, after adding error_log() 
messages in the PHP script, and a msDebug() call in mapscript_i.c: 
shapefileObj_destroy()

Note: doing 2 calls in a row to shapefile->free() will actually close the 
file... so this is definitely related to the reference counts that were added 
internally in PHP4.

[dmorissette]

Fixed at the same time as bug#30 ... was related to invalid handling of 
reference counts: the shapefileObj objects started with a refcount of 2.  This 
was caused by unnecessary add_ref calls that were added to avoid invalid 
_handle_ errors.  

See bug#30 for the full fix description.