fix missing stdin in _parallel_runner
Check for skipped tags in passed role variables before adding to them

Fixes #6330
Remove mention to AWS in Linode's inventory script.
Updates loop warning, removes unnecessary c
Merge pull request #6352 from sethwoodworth/patch-1

Spelling correction in loop warning, removes unnecessary c
Merge pull request #6351 from franckcuny/typo

Remove mention to AWS in Linode's inventory script.
Make this statement understandable grammatically
Merge pull request #6368 from jjshoe/patch-1

Make this statement understandable grammatically
Only used stripped data for testing if the file is json, but used unstripped when actually parsing. Fixes #6348
Merge pull request #6377 from sivel/issue/6348

Don't lstrip data to be parsed by parse_yaml. Fixes #6384
Merge pull request #6283 from magicrobotmonkey/upstream

fix missing stdin in _parallel_runner

Tested with GIST https://gist.github.com/risaacson/7290d30a612e0c70ea1b.
Passes "make tests"
Passes non_destructive tests.
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