'A Version \'satisfies\' another if it is at least as specific and has
a common prefix.  e.g., we want gcc@4.7.3 to satisfy a request for
gcc@4.7 so that when a user asks to build with gcc@4.7, we can find
a suitable compiler.'

@coerced
def satisfies(self, other):

    nself = len(self.version)
    nother = len(other.version)
    return ((nother <= nself) and (self.version[:nother] == other.version))
