Makes sure that the debug error message display survives DOM modifications.
Reduces the size of JavaScript emitted by HtmlWriter#writeAllGridJavaScript and changes it to not fire if the layout areas are already in the right order.
Improves grid debug display.
Merge branch 'release/2.1'

Conflicts:
	util/src/main/java/com/psddev/dari/util/HtmlWriter.java
Fixes CodeUtils instrumentation logic to be more backwards compatible.
Fixes compile error in Java 6 where it can't infer types correctly.