Fix apt module's boolean check to expect converted value

Fixes #2218.
Fix CliRunnerCallbacks.on_file_diff in callbacks.py

When running ansible -C, I get a traceback that ends with
    AttributeError: Values instance has no attribute 'diff'
This fixes on_file_diff to behave similar to
PlaybookRunnerCallbacks.on_file_diff().
Merge pull request #2221 from sfromm/fix-ansible-cli-check-mode

Fix CliRunnerCallbacks.on_file_diff in callbacks.py
Fix proxy env format

The incorrect format (e.g. http_proxy=http://proxy.bos.example.com:8080) gave this error: "environment must be a dictionary".
Merge pull request #2224 from cliffano/patch-1

Fix proxy env format
Squashed commit of the following:

commit e057ea671395ec8847f920a63cf9524f5c8fde5f
Author: Ton Kersten <tonk@tonkersten.com>
Date:   Thu Feb 28 13:02:25 2013 +0100

    Fixed the service command not working

    On Ubuntu 1[02].04 the service name was not recognized because
    there is a SysV style init script, but not an upstart config file.

    Example: The `ntp` client.

    Also removed extra spaces at the end of the lines, while at it.
Merge pull request #2231 from tonk/devel

Service command handling fix when no upstart config file
Use regular strings to allow tests to work
Fix references to user.username to be user.name
Fix bug from copy-paste
Merge pull request #2239 from marktheunissen/nolog-mysql

Fix bug from copy-paste
Squashed commit of the following:

commit 076501459322cf6c14de742e504339d80ffdeed5
Author: Ton Kersten <tonk@tonkersten.com>
Date:   Thu Feb 28 21:32:57 2013 +0100

    Added date and time facts to setup
Merge pull request #2241 from tonk/devel

Added dat and time facts to setup
Be consistent about underscore usage.
In django module if no virtualenv is specified, don't choke
Use relative creates/removes path with chdir