Remove LXC support.

The LXC driver was deprecated in Docker 1.8.
Following the deprecation rules, we can remove a deprecated feature
after two major releases. LXC won't be supported anymore starting on Docker 1.10.

Signed-off-by: David Calavera <david.calavera@gmail.com>

rewritten from github.com/moby/moby 3b5fac462d21ca164b3778647420016315289034

frontend/dockerfile/parser/testfiles/docker/Dockerfile

@@ -40,7 +40,6 @@ RUN	apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -yq \
 	libapparmor-dev \
 	libcap-dev \
 	libsqlite3-dev \
-	lxc=1.0* \
 	mercurial \
 	pandoc \
 	parallel \

frontend/dockerfile/parser/testfiles/docker/result

@@ -1,6 +1,6 @@
 (from "ubuntu:14.04")
 (maintainer "Tianon Gravi <admwiggin@gmail.com> (@tianon)")
-(run "apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -yq \tapt-utils \taufs-tools \tautomake \tbtrfs-tools \tbuild-essential \tcurl \tdpkg-sig \tgit \tiptables \tlibapparmor-dev \tlibcap-dev \tlibsqlite3-dev \tlxc=1.0* \tmercurial \tpandoc \tparallel \treprepro \truby1.9.1 \truby1.9.1-dev \ts3cmd=1.1.0* \t--no-install-recommends")
+(run "apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -yq \tapt-utils \taufs-tools \tautomake \tbtrfs-tools \tbuild-essential \tcurl \tdpkg-sig \tgit \tiptables \tlibapparmor-dev \tlibcap-dev \tlibsqlite3-dev \tmercurial \tpandoc \tparallel \treprepro \truby1.9.1 \truby1.9.1-dev \ts3cmd=1.1.0* \t--no-install-recommends")
 (run "git clone --no-checkout https://git.fedorahosted.org/git/lvm2.git /usr/local/lvm2 && cd /usr/local/lvm2 && git checkout -q v2_02_103")
 (run "cd /usr/local/lvm2 && ./configure --enable-static_link && make device-mapper && make install_device-mapper")
 (run "curl -sSL https://golang.org/dl/go1.3.src.tar.gz | tar -v -C /usr/local -xz")