replace 127.0.0.1 by the assigned IP address in the container's /etc/hosts file.
change 127.0.0.1 -> 127.0.1.1 & remove ::1 -> hostname mapping
Do not drop sys_boot

This fixes #2391
Merge remote-tracking branch 'upstream/master'

Conflicts:
	container.go
Container memory limit can be specified in kilobytes, megabytes or gigabytes

    -m 10  # 10 bytes
    -m 10b # 10 bytes
    -m 10k # 10240 bytes (10 * 1024)
    -m 10m # 10485760 bytes (10 * 1024 * 1024)
    -m 10g # 10737418240 bytes (10 * 1024 * 1024 * 1024)

Units are case-insensitive, and 'kb', 'mb' and 'gb' are equivalent to 'k', 'm' and 'g'.
Add known issues to sections via new "issues" extension.
Add known issues. Fix build warnings.
Updated Redis service example to use links
Check the output of iptables command.
Separate a) initialization of the http api and b) actually serving the api into 2 distinct jobs
Add ability to mount volumes in readonly mode using -volumes-from
Engine: 'start' starts the specified container
httpapi: don't create a pidfile if it isn't set in the configuration
Engine: fix a bug which caused handlers to be shared between multiple engine instances
Engine: don't export private testing utilities
Engine: improved logging and identification of jobs
Engine: optional environment variable 'Logging' in 'serveapi'
Removed redundant linking example
Hack: simplify the creation of test directories
Engine: fix a bug when encoding a job environment to json