discovery: introduce a obshash1 function using fm1 during hashing (issue4587) The 'fm0' serialisation translate float to text. This give different result between python2.6 and python2.7 (because python2.7 got smarter). The 'fm1' is all binary and expected to be stable so we introduce the ability to do the discovery using hash computed with 'fm1' serialisation. We use a new wireprotocol version (Partly because I'm too lazy to check how to add an argument to the existing one) and capabilities). Support in simple4server is will come in the next changeset.