feat #575 Improve documentation for the API viewer

Fix some typos and correct links to bean descriptions

Close #575
fix #589 Considering scrollbars width on Mac

When on mac the method aria.templates.Layout.getScrollbarsWidth() returns zero, due to the fact that on mac the scrollbars are managed differently. So in this case we add 17px in order to consider them and to avoid to crop some content.
fix #556 test fails on FF3.6: test.aria.widgets.form.checkbox.SetDisabledTest

Close #596
fix #588 explain why a frame cannot be loaded

Improve the logging in case a frame cannot be loaded and give it a bit more time to load.
If the iframe doesn't load correctly you might get exceptions like

````
'eval' is undefined
Could not complete the operation due to error 80020101.
````

This also overrides the mechanism for handling errors in `TemplateTestCase` to make sure that the template is disposed in case of errors.
It should make #587 less important, or useless, or an eye-candy while testing.
feat #500 utils.String.dashedToCamel|camelToDashed
fix #499 conform standards regarding dataset in Html.buildAttributeList

Added check for invalid keys passed to `dataset` in
utils.Html.buildAttributeList.

So far it only logs warning, to be switched in backward-incompatible
release.

Close #500.