Fixed #157: Display Image Dimension

Enabled by new preference "Show W x H".  You can see
Dimensions, Percent, both, or neither.

Localized into French and English but not other
lanugages.
Possible fix for hung script warning.

User reported a prompt from Firefox to stop a long-running script,
in overlay.js _getEffectiveTitleForNode().  I haven't been able
to reproduce it, but added an interation limit in the loop
for finding a caption title parent.

Also fixed an incorrect debug message call which might
have caused an exception.
Fixed tumblr.com thumbs outside of tumblr.com itself, eg on tumview.com,
http://tmv.proto.jp (tumblr mosaic viewer)
thinner pop-up border so it doesn't contrast as much with page background & photo
Changed white and blue border colors to be darker.

They now are less jarring against dark backgrounds.
partial support for an image site
3.2beta5