Remove WFS GetFeature response truncating

The restriction to the first 200 results of a WFS GetFeature request was done "by hand" in mapserverproxy because the "maxFeatures" limitation wasn't correctly taken into account by Mapserver. Mapserver 6.4 now support this parameter, therefore it is no longer necessary to do the truncating in mapserverproxy.

I suggest this change for GMF 1.5 so that projects using 1.4 may have time to upgrade Mapserver. Could we assume that Mapserver 6.4 will be a prerequisite for GMF 1.5?