Bugfix for footprint_poly; revised progress bar handling; bugfix for not resetting timeout start time; some further developments

compatibility.python.exceptions:
- FileNotFoundError: revised docstring

compatibility.gdal:
- refactored TranslateOptions to Translate

geo.raster.conversion:
- raster2polygon(): updated calls for progress bar and timeout

geo.raster.reproject:
- warp_ndarray(): updated calls for progress bar and timeout

geo.vector.topology:
- added fill_holes_within_poly()

io.raster.gdal:
- get_GDAL_ds_inmem(): implemented keyword 'nodata'

io.raster.GeoArray:
- GeoArray:
    - added many docstrings
    - projection.setter: revised assertion
    - footprint_poly(): bugfix for not consequently returning shapely.geometry.Polygon instances
    - save(): implemented keyword 'creationOptions': allows to pass creation options to GDAL writer

processing.progress_mon:
- replaced function is_timed_out() with new class 'Timer'
- replaced function printProgress() with new class 'ProgressBar'