amend: stop updating the bookmarks twice There was code to move the bookmarks around both in the 'cmdutil' help and in the main 'commit' function. We kill the 'commit' version as it is performed outside the transaction. The debug note is moved into cmdutil.

amend: collaborate with the transaction when moving bookmarks We have code moving bookmarks from the old changeset to the new one within the transaction scope. Yet this code was still writing to disk instead of handing the change to the transaction. This changeset fixes this.

sshserver: drop ancient do_{lock,unlock,addchangegroup} methods These were marked as deprecated and dangerous way back in e8c4f3d3df8c, which was first included in Mercurial 0.9.1. While it's possible that clients from that long ago are still around somewhere, they're risky for servers in that they want to lock the repo, and then might leave it locked if they died before finishing their transaction. Given that it's been 9 years, let's go ahead and cut this last lingering tie with a basically-untested protocol.

wireproto: add config knob for http header length limit Well-behaved Mercurial clients will respect the httpheader capability by not sending http headers longer than the given limit in bytes. The limit is currently hard-coded at 1024 bytes, a safe value for any web server. Since parsing headers is a notable factor in web server performance, tuning header size can nontrivially improve performance for request-heavy operations (eg. obsolete marker negotiation). Exposing the maximum header length limit as a configuration setting is a simple way to enable such tuning.