Add margin on code blocks and tables
Merge pull request #481 from BramChen/master

Add chinese translation of canned filters
Fix problem with refreshing D3 plugin

Fixes #217
Update test of tagging filter to reflect 0d7c4ae6c7e82ec6c360f79d6b1b7964cabb441a
Restore visibility of system tags in view template

On discussion at Hangout #38 we felt that hiding them was confusing,
and that there were few situations where a user would see system tags
except on system tiddlers.