doc/README: simplify instructions

doc: use our own rst2man.py script (issue1746) The rst2man tool has not yet been part of an official Docutils release, and it is not present in most distributions. This poses a problem for people who want to install Mercurial from source, or who want to create a Mercurial package for such a distribution -- how to specify the build-dependencies? By including the rst2man.py script with Mercurial people only need a normal Docutils installation in order to install Mercurial.

util, minirst: do not crash with COLUMNS=0

manifestdict: remove unnecessary dictionary copy No need to copy the dict, dict.__init__() will do that for us. It was responsible for a non-negligeable waste of time during a qpush of an -mm queue on the kernel repo.

manifest.add(): cleanup worklist construction and iteration

manifest: simplify cache handling, use a unique cache

manifest.add(): simplify with iterators and generator expressions

color: do all setup in uisetup Now that extensions are loaded in phases, we are guaranteed to always find mq in uisetup with extensions.find and we know that the mq commands are not yet copied into commands.table.

extensions: pass ui arguement to extsetup if accepted

extensions: load and configure extensions in well-defined phases Extensions are now loaded with a call-graph like this: dispatch._dispatch extensions.loadall extensions.load # add foo module to extensions._extensions extensions.load # add bar module to extensions._extensions foo.uisetup(ui) bar.uisetup(ui) foo.extsetup() bar.extsetup() commands.table.update(foo.cmdtable) commands.table.update(bar.cmdtable) hg.repository foo.reposetup(ui, repo) bar.reposetup(ui, repo) The uisetup calls could easily be moved out to dispatch._dispatch, but have been kept in extensions.loadall since at least TortoiseHg calls extensions.loadall and expects it to call uisetup. The extensions.load function called uisetup. It now has an unused ui argument which has been kept for backwards compatibility.