Change hard coded series fallback for LatestLtsSeries() to trusty (from precise)
Fix typo
Fix typo
Fix tests
Upload correct tools to fix tests
Fix a manual test
Merge pull request #711 from wallyworld/default-lts-trusty

Change hard coded series fallback for LatestLtsSeries() to trusty

Fixes:
https://bugs.launchpad.net/bugs/1315473
https://bugs.launchpad.net/bugs/1363971

The LatestLtsSeries() detection had a hard coded fallback to "precise" when the call to 'distro-info --lts' fails. The fallback is changed to "trusty". 

This covers the add-machine case (whether adding a container or a new machine) where the default-series config value is not specified.