Add windows userdata support

* refactor cloudinit packages to include support for windows userdata
* fix NewMachineConfig to store corect paths when on windows
Added tests for windows userdata
Changes made based of feedback
state/api/{keyupdater,networker}: use names.Tag

Use tags not strings on api methods.
Initial merge of 1.20 into master
corresponding changes to worker/
Merge pull request #548 from davecheney/182-state-api-use-tags

state/api/{keyupdater,networker}: use names.Tag

Use tags not strings on api methods.
Add extra logging
Update deps for utils package update
Merge pull request #549 from wallyworld/merge-1.20

Merge of 1.20 into master

This PR merges 1.20 into master to ensure nothing done for 1.20 has slipped through the cracks. After resolving all conflicts, the only remaining change is the recently committed 1.20 work to make lxc containers copy tools from the file system.
provider/maas: report arch matching tools in tests

The architecture of the instances must match the
architecture of the tools uploaded, which is the
same as version.Current.Arch in the tests.

__fixes-1358768__
Merge pull request #552 from axw/lp1358768-provider-maas-i386

provider/maas: report arch matching tools in tests

The architecture of the instances must match the
architecture of the tools uploaded, which is the
same as version.Current.Arch in the tests.

__fixes-1358768__
rsyslog: add logrotate for all-machines.log
rsyslog: logrotate comments and docs
rsyslog: logrotate tests
rsyslog: check for logrotate files, updated comments
rsyslog: only render templates once, improve file check test
rsyslog: comments for exported functions
Merge pull request #550 from wallyworld/juju-utils-update

Update deps for utils package update

Fixes bug https://bugs.launchpad.net/bugs/1354685
rsyslog: updated documentation, simplified logrotate file rendering.