implemented point-wise read processes in GeoArray

geo,vector.topology:
- fill_holes_within_poly(): bugfix for not checking if polygon has holes in case input poly geom_type=='Polygon'

geo.coord_trafo:
- mapXY2imXY(): now also accepts 2D coordinate pair arrays
- imXY2mapXY(): now also accepts 2D coordinate pair arrays

io.raster.GeoArray.GeoArray:
- added function read_pointData(): allows vectorizes point-wise read processes
- __getitem__(): bugfix for wrong return value in case the elements of 'given' contain lists -> allows vectorizes point-wise read processes