make pyflakes a bit more silent

- explictely import json, since this is used ( only to silence pyflakes)
- remove shutil as it is unused
remove unused variable (pyflakes)
fix incorrect send_data call. there is no client variable, and send_data
is a class method. Pyflakes complained about it.
Support retrieving EC2 state/previous_state when using newer versions of Boto.
Check real user's known_hosts when sudo ansible...

closes #4834
Apply the same change as https://github.com/hnakamur/ansible-playbooks/pull/2
Fix homebrew module's install_options handling

...each given option must be a single element in the
arguments list passed as first argument to module.run_command()
return failed if a package couldn't be installed

For some reason, on my test mandriva, urpmi --force return 0
even when it cannot install a rpm. So we have to explicitely check
if the package was properly installed with a loop
Correct the constant name "remote_temp" to "remote_tmp"
Improve Group.get_hosts() performance.

- reduce hosts group list to unique elements faster
- add a cache of already computed hosts group list
Revert "Merge pull request #4912 from zehome/openbsd_pkg_flavourfix"

This reverts commit de2f4cf04d13b24dc56114da1ab63245c5868c34, reversing
changes made to 2c33737bfa3b2e7286ada2f2f7bba57317f2b885.
KeyError: 'delegate_to' no more
Fixes #4851 Set syslog debug mode for accelerate properly
Fixes #4852 properly evaluate log_path writability
correct link to developing modules on ansible work's website
Merge pull request #4947 from bob-smith/devel

correct link to developing modules on ansible work's website
correct link to developing modules on ansiblework's website (part 2)
Merge pull request #4948 from bob-smith/devel

correct link to developing modules on ansiblework's website (part 2)
Merge pull request #4937 from skyl/synchronize-keyerror

KeyError: 'delegate_to' lookup in sync module needs to be checked to see if defined for ad hoc
Merge pull request #4842 from cchurch/devel

Retrieve EC2 state when using newer versions of Boto