loader readme update
Bump HISTORY version to 3.13.0
Bump SINCE version to 3.13.0
Bump version to 3.13.0-rc-1
Build modules with SINCE version bumps
json: Fix freeze/thaw test to work with IE8

`node.get('innerHTML')` was adding in `<BR>` line breaks, causing
`JSON.parse` to throw a syntax error.
valuechange: Fix error when `vcData` is null

Changes check for `nodeName` to only occur after vcData is
shown to be non-null.
Merge branch 'valuechange-bugfix' into release-3.13.0
valuechange: Build files
Merge branch 'loader-readme' into release-3.13.0
Merge branch 'editor' into release-3.13.0

Conflicts:
	package.json