added start of code for enumerating relevant vectors
ran first test of relevant vector code.  Works fine with Zn.  Needs tests with An etc.  Also should automate the tests from check from the strict relevant vectors in known cases.  I had not quite realised that when there are lax relevant vectors you end up with more than 2^(n+1)-2.  It's obvious really since it occurs for the integer lattice.  This isn't really of consequence since the strict vectors are the interesting ones.
minor