Fix release date
Merge HISTORY and CHANGES
build: make the 'doc' target generic
Version 4.7.1
Update Max' contact data
Tweak CHANGES file for release automation
removed "static" from HTAdd_TreeHash_C and HTValue_TreeHash_C, so that I can use them in semigroups.c. JDM
Fix error in Memory() method for orbit-by-suborbit setup objects

Reported (with fix) on GAP support by Lukas Gröber)
Merge branch 'master' of https://github.com/james-d-mitchell/orb

Conflicts:
	src/orb.c
Merge commit 'e1c0419d36d583e7a2d91e0725fe3fde9b5661e7'