Major bugfix/feature: the `fabfile` should work even if local/remote are different OS type (eg. OSX to Linux, or Linux to OSX). Previously the targets worked because I used them either on same system types, or via `-H localhost`. This feature needed a consequent rewrite to be able to automatically fetch remote information *after* `Fabric` is initialized, and to avoid fetching them for every task when they are nested.
Merge branch 'release/1.3'
Merge tag 'sparks-1.3' into develop

1.3