NSM preparation for OSX and windows

NSM preparation for OSX and windows

Note that on those platforms the application name
is a full path. This is permitted by the specs:

“executable_name MUST be the executable name that the program was launched with. For C programs, this is simply the value of argv[0]” [http://non.tuxfamily.org/nsm/API.html#n:1.2.1.1.]

but the current implementation of nsm expects the basename
only and searched $PATH.