remove virtual phase band from SLC products
update json files without the phase bands
insert new menus before the window and help menu positions
Merge pull request #4 from arraydev/envisat-reader

Envisat reader: remove virtual phase bands from SLC products (ASAR)
Merge pull request #6 from arraydev/menu_insertion

insert new menus before the window and help menu positions
set version of seadas-reader to 1.6
set version of seadas-reader to 1.5.6