fixed a lot of incompatibilities caused by only partial revisions; some bugfixes => version now fully operable again

imParamObj:
- bugfix for not recognizing nodata values if 0
- bugfix for not setting  imParamObj.nodata in case of inmem-GeoArray
- added automatic fix of invalid footprint polygon

COREG:
- implemented new keyword argument 'path_verbose_out'
- set_outpathes(): major revision
- added calc_integer_shifts()
- added validate_integer_shifts()
- calculate_spatial_shifts(): simiplified implementation of the algorithm
- added some comments to calculate_spatial_shifts()
- get_updated_map_info(): reordered print outputs
- revised correct_shifts()
- refactored shift_image_by_updating_map_info() to _shift_image_by_updating_map_info()
- refactored align_coordinate_grids() to _align_coordinate_grids()
- refactored resample_without_grid_aligning() to _resample_without_grid_aligning()

DESHIFTER:
- implemented new keyword 'path_out'
- added object attribute self.align_grids
- correct_shifts(): added some comments and the possibility to write results to disk

Geom_Quality_Grid:     fixed some incompatibilities caused by revision of COREG and DESHIFTER; much faster multiprocessing by avoiding duplicated disk IO
- __init__():
    - added docstring to __init__()
    - implemented possibility to pass a GeoArrays as arguments to __init__()
    - some code style changes
    - added nodata attribute
- _get_imXY__mapXY_points(): revised  calculation of outer map coordinates
- revised _get_spatial_shifts(): now self don't has to be pickled anymore if called in multiprocessing -> much faster multiprocessing
- revised get_quality_grid() and implemented new call of _get_spatial_shifts()

MAIN:
- added parameter -vo (path verbose out)