record: unconditionally update the working dir after patching

mq: explicitly updatedir() even if patch() fails It already works that way in practice, and we intend to merge updatedir() into patch().

mq: allow to qpop/push with a dirty working copy (issue2780) It's safe to do so if the sets of changed files in the working copy and patches are disjoint.

patch: introduce changedfiles returns the set of all changed files in a given patch

debugindex: change output for generaldelta revlogs For generaldelta revlogs, reporting the deltaparent instead of the chain base makes more sense, since that's what's actually stored in the revlog.

revlog: support reading generaldelta revlogs Generaldelta is a new revlog global flag. When it's turned on, the base field of each revision entry holds the deltaparent instead of the base revision of the current delta chain. This allows for great potential flexibility when generating deltas, as any revision can serve as deltaparent. Previously, the deltaparent for revision r was hardcoded to be r - 1. The base revision of the delta chain can still be accessed as before, since it is now computed in an iterative fashion, following the deltaparents backwards.

revlog: calculate base revisions iteratively This is in preparation for generaldelta, where the revlog entry base field is reinterpreted as the deltaparent. For that reason we also rename the base function to chainbase. Without generaldelta, performance is unaffected, but generaldelta will suffer from this in _addrevision, since delta chains will be walked repeatedly. A cache has been added to eliminate this problem completely.

revlog: remove the last bits of punched/shallow Most of it was removed in e7483ec3c374, but a few pieces were accidentally left behind.

util: make readfile() operate in binary mode writefile() and appendfile() are already working that way.

cmdutil: normalize log message eols when reading from file This will be necessary once util.readfile() operates in binary mode. While changelog.add() already normalizes the message, doing so in logmessage() is required as ui.edit() or others expect messages with LF only.

match: make 'listfile:' split on LF and CRLF We want util.readfile() to operate in binary mode, so EOLs have to be handled correctly depending on the platform. It seems both easier and more convenient to treat LF and CRLF the same way on all platforms.

progress: remove useless statement left by bab267e7fc1a

debugbuilddag: simplify tags serialization a bit

httprepo: send 100-continue on POSTs if using http2

url: use new http support if requested by the user The new http library is wired in via an extra module (httpconnection.py), as it requires similar but different plumbing to connect the library to Mercurial's internals and urllib2. Eventualy we should be able to remove all of keepalive.py and its associated tangle in url.py and replace it all with the code in httpconnection.py. To use the new library, set 'ui.usehttp2' to true. The underlying http library uses the logging module liberally, so if things break you can use 'ui.http2debuglevel' to set the log level to INFO or DEBUG to get that logging information (for example, ui.http2debuglevel=info.)