update fabric plugin documentation
apply review fixes
Merge pull request #135 from cloudify-cosmo/fabric-plugin-docs

update fabric plugin documentation
update plugin authoring guide
small fixes
remove type/relationship implementation from terminology page
fix cfy ref docs
Merge pull request #140 from cloudify-cosmo/update-plugin-authoring

update plugin authoring guide
small fixes to the script plugin docs
update chef plugin docs
fix windows agent install docs
update readthedocs references
update puppet docs
get_input intrinsic function documentation
dsl spec - functions