Avoid loading node html if disableEditor set

[knolleary]

• New feature (non-breaking change which adds functionality)

Proposed changes

This change modifies how nodes are loaded so that if disableEditor is set, we now skip loading the node html into memory.

This shaves a small amount off the startup time - not as much as I'd hoped. But it will save a bit of memory usage.

It still loads the locales files as a node may have runtime messages in its catalog.

Checklist

• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[coveralls]

Coverage decreased (-0.2%) to 77.072% when pulling 33855bc on skip-html into bcd85b1 on dev.