test: more resistance to filtering changes

merge with stable

support -r option in prune, add a test for this Also localize options in fold.

doc: index version info on index

doc: updates mq refugee book

doc: update how-to

tutorial: second replacement of hg amend by commit --amend (the diff is huge because commit --amend have protection vs cycle)

tutorial: use evolve directly We a real mode in addition to the dry run one.

tutorial: use rebase instead of graft -O

tutorial: use commit --amend when possible commit --amend is the core way to do that, we better get used to it.

evolve: make evolve smarter It is not more confused by killed changeset and can also choose to stabilise '.'

tutorial: update notes in unwritten section

tutorial: glog is into core now

test: adapt to the way the bundle is generated optimised generation gives 1 changes, strict on gives 2.

fold: work around potential bug with filtering Folded revision may be becomes filtered leading to a crash of the replaced rset.

prepare for filtering