Avoid unnecessary dependence graphviz.

Suites can now run, and gcylc can be used (minus the graph view) if
graphviz/pygraphviz is not installed.
Updated the change log.
Plot naked dummy tasks in namespace graphs.

Closes #338.
Recognise that localhost is not a remote host.
Merge pull request #354 from hjoliver/338-graph-naked-dummy-tasks

Plot naked dummy tasks in namespace graphs.
Merge branch 'master' into localhost-not-remote
Merge pull request #352 from hjoliver/347-dependence-on-graphviz

Fixes #347 - dependence on graphviz
Merge branch 'master' into localhost-not-remote
Merge pull request #356 from matthewrmshin/localhost-not-remote

Recognise that localhost is not a remote host.
Corrected a typo in suite host hard-wiring code.

Closes #259.
Merge pull request #357 from hjoliver/259-suite-host-typo

Corrected a typo in suite host hard-wiring code.
Factor out Jinja2 dependence.

Suites that do not use Jinja2 don't need Jinja2 to be installed.
Merge pull request #359 from hjoliver/factor-out-jinja2-dependence

Factor out Jinja2 dependence.