hgweb: use our forked wsgiheaders module instead of stdlib one Now we use bytes for headers, rather than native strings. Differential Revision: https://phab.mercurial-scm.org/D2854

wsgiheaders: import a bytes-ified fork of wsgiref.headers from cpython@46f5072 This will let us restore Python 3 compatibility for tests that do http things. Differential Revision: https://phab.mercurial-scm.org/D3245

export: enable formatter support (API) This change is basically the same as "hg cat". A formatter object is created by caller. .. api:: ``cmdutil.export()`` takes a formatter as an argument.

export: extract function to write patch to file object (API) This is common use case of cmdutil.export(), and we wouldn't want to handle formatter thingy everywhere. .. api:: The ``fp`` argument is removed from ``cmdutil.export()``. Use ``cmdutil.exportfile()`` instead.

export: port _exportsingle() to formatter Pass 'fm' instead of 'write', and use fm.plain(), fm.write(), etc. instead. The callers will be updated later.

export: serialize revisions to be exported per destination file Prepares for porting to the formatter API, where we can't simply append to existing files because JSON can't be streamed for example. The modemap hack is removed since cmdutil.export() was the only user. I also made the destination filename printed only once.

export: split cmdutil.export() to single-file and maybe-multiple-files cases Porting "hg export" to formatter is a bit hard because cmdutil.export() may append to files if the fntemplate is specified. This patch splits the hard part from the trivial case.

export: remove unused argument 'rev' from _exportsingle()

export: do not start pager if output will be written to file A copy of 3b569745af6c.

formatter: carry opts to file-based formatters by basefm This makes it slightly easier to port "hg export" to formatter.