tests/failfilemerge.py

packaging: add make target for linux wheels

Having linux wheels is going to helps system without compiler or python-dev
plus speed up the installation for everyone.

I followed the manylinux example repository
https://github.com/pypa/python-manylinux-demo
to add a make target (build-linux-wheels) using
official docker image to build python 2 linux wheels
for mercurial. It generates Python 2.6 and Python 2.7 for both
32 and 64 bits architectures.

I had to blacklist several test cases for various reasons:
* test-convert-git.t and test-subrepo-git.t because of the git version
* test-patchbomb-tls.t because of warning using tls 1.0
  It's likely because the docker image is based on centos 5.0 and
  openssl is outdated.

# extension to emulate interrupting filemerge._filemerge

from __future__ import absolute_import

from mercurial import (
    error,
    extensions,
    filemerge,
)

def failfilemerge(filemergefn,
                  premerge, repo, mynode, orig, fcd, fco, fca, labels=None):
    raise error.Abort("^C")
    return filemergefn(premerge, repo, mynode, orig, fcd, fco, fca, labels)

def extsetup(ui):
    extensions.wrapfunction(filemerge, '_filemerge',
                            failfilemerge)