[Bf-compositor] [enh] thumbnail previews + node border color

[Jeroen Bakker]

Hi All,

The changes for thumbnail previews and node border colors have been 
merged with trunk.

In the compositor only the input previews will be visible by default. 
all others are made invisible. Via the hide/show preview these can still 
be made visible.

The node colors can be altered in the UserPreferences. We should poke 
the themes maintainers to update their themes.
Also there is a small glitch that need to be updated by them.

Please give us feedback about the usage. So what would be our next priority?

Regards,
Jeroen & Monique
  - At Mind -