Pick up default EC2 region from boto.config

This doesn't account for boto configs where e.g. RDS has one
default region and EC2 another - all will default to `ec2_region_name`.

However, this is just handy to allow an easy site wide default
region if existing configuration already relies on it.

Modules can be improved to mention this in the documentation and
turn off required=True where needed. But it works with `ec2`
and `ec2_vol` without change.
Adding the region to the output of the ec2 module's creation of a new instance.
When looking for double colon len(line) is longer then 1.

Addresses GH-5116.

It comes up that when parsing json that if you are missing the last double quote on the last variable and the next line is just '}' we will get an out of range error. In this instance we will also then make sure that the line is long enough to have two colons.
Merge pull request #5689 from pgehres/devel

Adding the region to the output of the ec2 module's creation of a new in...
Merge pull request #6197 from risaacson/issues_5116

When looking for double colon len(line) must be longer then 1.
Add expanduser calls on src/dest in the module too
And remove the expanduser calls from the action_plugin
Merge branch 'ec2_boto_config_region' of https://github.com/willthames/ansible into willthames-ec2_boto_config_region
Minor tweak to region config in boto configuration file
column must always be less than len(probline)

Fixes related to GH-5773.
Merge pull request #6199 from risaacson/issues_5773

column must always be less than len(probline)
Micro-optimization of inventory.expand_hosts.detect_range
Micro-optimization: replace s.find(x)!=-1 with x in s

timeit shows a speedup of ~3x on Python 2.7.5 x86_64.
It also makes the code a bit shorter.
hostname module: don't filter hostnamectl with awk

There's no need to filter hostnamectl's output with awk because its man
page says:

    hostnamectl [OPTIONS...] {COMMAND}

       --static, --transient, --pretty
	   If status is used (or no explicit command is given) and one
	   of those fields is given, hostnamectl will print out just
           this selected hostname.

E.g. hostnamectl --static status => ansible.example.org