Added option nomem
added **kwargs to add_bands function and call to VRT initialization
replaced kwargs by nomem=False
Added option to save vrt on disk instead of in memory
Merge branch 'issue23' into develop
Added doc for resolution in write_map function
changed from colon to comma in the docstring
#22 if input filename is same as output in export(), copy and add all bands and delete source bands.
Merge branch 'issue22' into develop
Merge branch 'develop' into issue17