merge with stable
tests: use locate to find files for pyflakes check

Based on a suggestion by Yuya Nishihara
check-code: look at shebang to identify Python scripts
test-check-code-hg: use test-repo check
test-check-code-hg: drop manual check of non-.py scripts
test-check-code-hg: use locate instead of manifest
factotum: initialize global variables to suppress pyflakes warning
merge with stable
run-tests: initialize global variables to suppress pyflakes warning
test-pyflakes: detect undefined name error

It should be able to catch the following mistakes at 2606e7f227f6:

    mercurial/exchange.py:590: undefined name 'UnknownPartError'
    mercurial/match.py:346: undefined name 'pat'
    mercurial/win32.py:365: undefined name '_ERROR_NO_MORE_FILES'
    tests/killdaemons.py:46: undefined name 'check'
histedit: use "editor" argument of "commit()" instead of explicit "ui.edit()"

Before this patch, "message" action of "hg histedit" uses "ui.edit()"
explicitly to get commit message edited manually.

This requires explicit "localrepository.savecommitmessage()"
invocation to save edited commit message into ".hg/last-message.txt",
because unexpected exception raising may abort command execution
before saving it in "localrepository.commit()".

This patch uses "editor" argument of "localrepository.commit()"
instead of explicit "ui.edit()" invocation for "message" action of "hg
histedit"

"localrepository.commit()" will invoke "editor()" function newly added
in this patch, and save edited commit message into ".hg/last-message.txt"
automatically.
qnew: use "editor" argument of "commit()" instead of explicit "ui.edit()"

Before this patch, "hg qnew" invokes "ui.edit()" explicitly to get
commit message edited manually.

This requires explicit "localrepository.savecommitmessage()"
invocation to save edited commit message into ".hg/last-message.txt",
because unexpected exception raising may abort command execution
before saving it in "localrepository.commit()".

This patch uses "editor" argument of "localrepository.commit()"
instead of explicit "ui.edit()" invocation for "hg qnew".

"localrepository.commit()" will invoke "desceditor()" function newly
added by this patch, and save edited commit message into
".hg/last-message.txt" automatically.

This patch passes not "editor" but "desceditor" to "commit()", because
"hg qnew" requires editor function to return edited message if not
empty, or default message otherwise.

This patch applies "rstrip()" on "defaultmsg" at comparison between
"nctx.description()" and "defaultmsg", because the former should be
stripped by "changelog.stripdesc()" and the latter may have tail white
spaces inherited from "patchfn".
qrefresh: relocate message/patch-header handling to delay message determination

Before this patch, commit message for refreshed MQ changeset is
determined, and written into refreshed patch file before
"localrepository.commit()" invocation.

This makes refactoring to use "editor" argument of "commit()" instead
of explicit "ui.edit()" invocation in succeeding patch difficult.

This patch relocates message/patch-header handling to delay message
determination.
qrefresh: use "editor" argument of "commit()" instead of explicit "ui.edit()"

Before this patch, "hg qrefresh" and "hg qfold" invoke "ui.edit()"
explicitly to get commit message edited manually.

This requires explicit "localrepository.savecommitmessage()"
invocation to save edited commit message into ".hg/last-message.txt",
because unexpected exception raising may abort command execution
before saving it in "localrepository.commit()".

This patch uses "editor" argument of "localrepository.commit()"
instead of explicit "ui.edit()" invocation for "hg qnew" and "hg qfold"

"localrepository.commit()" will invoke "desceditor()" function newly
added by this patch, and save edited commit message into
".hg/last-message.txt" automatically.

This patch passes not "editor" but "desceditor" to "commit()", because
"hg qnew" and "hg qfold" require editor function to return edited
message (and invoke "patchheader.setmessage()" with it) if not empty,
or default message otherwise.

This patch also avoids "not q.applied" check at "hg qrefresh --edit",
because it is also checked in "queue.refresh()", and it is not needed
to get commit message from patch header before "queue.refresh()".
localrepo: add "editor" argument to "tag()"

Before this patch, "localrepository.tag()" doesn't take "editor"
argument, and this prevents callers from passing "editor" argument to
"localrepository.commit()" invoked internally.

This patch adds "editor" argument to "localrepository.tag()" (and
"_tag()", too), and makes "commands.tag()" invoke it with "editor"
argument.

This patch also omits explicit "localrepository.savecommitmesssage()"
invocation, because "localrepository.commit()" will invoke specified
"editor" and save edited commit message into ".hg/last-message.txt"
automatically.
context: move editor invocation from "makememctx()" to "memctx.__init__()"

This patch introduces "editor" argument to "memctx.__init__()", and
moves editor invocation from "makememctx()" to "memctx.__init__()", to
centralize editor invocation into "memctx" object creation.

This relocation is needed, because "makememctx()" requires the "store"
object providing "getfile()" to create "memfilectx" object, and this
prevents some code paths from using "makememctx()" instead of
"memctx.__init__()".

This patch also invokes "localrepository.savecommitmessage()", when
"editor" is specified explicitly, to centralize saving commit message
into "memctx" object creation: passing "cmdutil.commiteditor" as
"editor" can achieve both suppressing editor invocation and saving
into ".hg/last-message.txt" for non empty commit messages.
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.
amend: use "editor" argument for "memctx.__init__" to save commit message

This patch uses "editor" argument of "memctx.__init__" to save commit
message, instead of explicit editor invocation and saving commit
message by "localrepository.savecommitmessage()".

By passing one of "commiteditor" or "commitforceeditor" as "editor",
"memctx.__init__" saves commit message, even when editor invocation is
not needed.
cmdutil: omit redundant "savecommitmessage()" in "tryimportone()"

The preceding patch causes that "makememctx()" with "editor" argument
saves (manually edited) commit message into ".hg/last-message.txt":
saving itself is executed indirectly in "memctx.__init__()".

This makes it redundant to invoke "savecommitmessage()" on caller side
of "makememctx()".

This patch omits such redundant "savecommitmessage()" invocation in
"tryimportone()".

"tryimportone()" uses one of "commiteditor" or "commitforceeditor" as
"editor" argument, and this causes saving commit message always.
largefiles: declare commands using decorator