Revert "Added last edit of ASAR mapper from issue57-sar-azimuth"

This reverts commit 368bdef20808311a104a902055dba39039d8e5d3.
Revert "Fixed bug in ASAR/MERIS helper class Envisat: modifying hardcoded list of units affects subsequent calls to get_array_from_ADS function"

This reverts commit 44d985561c036f5e4517f2a79a1850a05a07e9e7.
Revert "ASAR mapper now calculates and stores SAR look direction, available as lazy operation on small ADS array"

This reverts commit 74e6d5ea7f98dbc91149f9b9e6288e321e03e45c.
Revert "Cleanup of ASAR mapper and corresponding Envisat class/module (by/with Anton). ASAR now adds incidence angle through new mechanism, going through small Nansat object."

This reverts commit 32f5110b64d30c2f880fe84deedfb3ade282f79c.