[ENH] Image magnification feature added to image plugin.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@48192 b456876b-0849-0410-b77d-98878d47e9d5
[ENH] CodeMirror upgraded to latest stable version (3.16).

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@48193 b456876b-0849-0410-b77d-98878d47e9d5