cachevfs: add a vfs dedicated to cache Most of the cache content lives in '.hg/cache/'. Moreover they are computed exclusively from data in the '.hg/store' directory. This creates issues with the share extension as the '.hg/store' directory is shared but the '.hg/cache' is not. On large repositories, this makes this prevent some usage of the share extension inefficient as some caches can take minutes to be recomputed. To improve the situation, we introduce a new 'cachevfs' that will be dedicated to cache reading and writing. In the next patches of this series, we'll migrate the 4 existing caches to it and update the share extension.

Mercurial
=========

Mercurial is a fast, easy to use, distributed revision control tool
for software developers.

Basic install:

 $ make            # see install targets
 $ make install    # do a system-wide install
 $ hg debuginstall # sanity-check setup
 $ hg              # see help

Running without installing:

 $ make local      # build for inplace usage
 $ ./hg --version  # should show the latest version

See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.