allows to break out of $tw.utils.each

Will improve performance with `$tw.utils.each` callbacks breaking out of
the iteration via `return false;`.
code style revision

thanks, Jeremy... will watch out for that
Fix type "importer" should be "exporter"
Merge pull request #1151 from malgam/patch-1

Fix typo "importer" should be "exporter"
Preparing for 5.1.6
Fix problem with edit-bitmap widget static rendering

The ‘introduction’ edition contains an edit-bitmap widget that was
failing under Node.js because the fake dom doesn’t support canvas.
Add Dutch TiddlyWiki blog post
Adjust default dropdown width

To avoid text of exporter descriptions overflowing on Firefox.

We need a better solution. On Chrome, nested popups resize to fit their
content, without being constrained by the parent width.
Add highlight plugin to /dev wiki
Palette tweaks for /dev
External links need a protocol as well?

They don't work for me without 'http://'. Firefox 33.1.1.
missing verb

also added the begining of the sentence to make it clearer, but maybe not necessary.
added object as third parameter to callback
list core descriptions for ModuleType

changed dead links with descriptions ...these are still missing:

* $:/language/Docs/ModuleTypes/allfilteroperator
* $:/language/Docs/ModuleTypes/info
* $:/language/Docs/ModuleTypes/library
Add experimental system tiddler browser
Use a serif font for /dev edition

For variety
Add parameter docs for tabbed toc macro
Merge pull request #1181 from tobibeer/patch-1

list core descriptions for ModuleType
Merge pull request #1145 from tobibeer/allow-to-break-each

allows to break out of $tw.utils.each
Coding style cleanup