- fixing tests so other tests are not ignored if rtree isn't installed
- fixing tests so other tests are not ignored if rtree isn't installed

AlanZatarain/pysal,tectronics/pysal,pombreda/pysal,pombreda/pysal,google-code-export/pysal,google-code-export/pysal,google-code-export/pysal,google-code-export/pysal,pombreda/pysal,tectronics/pysal,AlanZatarain/pysal,tectronics/pysal,pombreda/pysal,Alwnikrotikz/pysal,Alwnikrotikz/pysal,AlanZatarain/pysal,Alwnikrotikz/pysal