histedit: pass "editor" argument to "memctx.__init__()" for "collapse" command
The preceding patch causes that "memctx.__init__()" with "editor"
argument invokes editor and saves edited commit message into
".hg/last-message.txt".
This patch passes "editor" argument to "memctx.__init__()" instead of
explicit invocations of "commitforceeditor()" and
"savecommitmessage()" for "collapse" command.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..