Add -S option to tar for efficient sparse file handling

Fixes issue #3282
Return error if Dockerfile is empty
Allow mtu to be configured at daemon start
Only parse upto the mountpoint in mountinfo
Merge pull request #3294 from discordianfish/3293-better-error-dockerfile-empty

Return error if Dockerfile is empty
Merge pull request #3291 from dineshs-altiscale/3282-sparse-files

Add -S option to tar for efficient sparse file handling
Merge pull request #3300 from crosbymichael/fix-mountinfo-parsing

Only parse upto the mountpoint in mountinfo
Merge pull request #3289 from crosbymichael/add-mtu-option

Allow mtu to be configured at daemon start
network: fix a typo in udp cleanup path

Fix #3224 - Port already in use error when running a container

Signed-off-by: Tzu-Jung Lee <roylee17@gmail.com>
Merge pull request #3306 from roylee17/3224-fix-udp-cleanup

network: fix a typo in udp cleanup path
Change an to a
Merge pull request #3272 from SvenDowideit/more-complete-run-cmd-example

A more complete example of docker run.
Merge pull request #3308 from crigor/patch-1

Change an to a
use the Makefile - it makes life so much simpler