commands: disallow 'hg debugobsolete --index --rev <smth>' A bug in the original --index implementation. The goal of --index is to allow unique obsmarker identification that would be consistent between invocations of this command in the unchanged repo. Further goal is to use this index to delete arbitrary obsmarkers. So calling --index together with --rev would cause obsmarker indices to be different than just calling --index. This is not desired and current pattern for getting the index of an interesting obsmarker is: `$ hg debugobsolete --index | grep <interesting hash>`. It would clearly be better if we could somehow compute a hash of an obsmarker and use it to identify the one we want to delete, but it seems a bit too heavy for our current goals, so we can do this later if we want.

mercurial: add editorconfig Editorconfig (http://editorconfig.org/) is a file format helping define coding styles like spaces, tabs etc. It supports a wide range of editors. Some well- known projects like ruby and zsh are using it already. This patch adds a simple .editorconfig, making it clear we use 8-char tabs in C code, 4-char spaces in Python code, and we don't keep trailing spaces.

parsers: fix istat macro to work with single line if statement

pypy: fix setdiscovery test This test relies on the exact details of random.sample given the seed. Things work a bit differently under pypy, make the test less specific.

chg: wrap line at 80 chars This is a style fix. I was using tabstop=4 for some early patches, although I realized we use tabstop=8 later but these early style issues remains. Let's fix them.

chg: replace abortmsg showing errno with abortmsgerrno Since we have abortmsgerrno now, use it to show human friendly error messages across platforms.

chg: add util function abortmsgerrno to print error with errno It's common to abortmsg with the errno information. Let's make a utility function for it.