Removes long deprecated properties of SC.TextFieldView: isPassword & continuouslyUpdatesValue. Starts standardizing to true/false.
Improves hint implementation of SC.TextFieldView. Previously, there were 3 ways to display the hint: via placeholder attribute, via a text overlay or via setting an initial value of the input field. The last way, setting the value of the input, is the oldest method and the least useful, because it requires a lot of extra work to modify the type of the input when it is a password field into a text field. This work is made even worse because Internet Explorer doesn't allow you to modify the type of the field and so the code gets quite ugly and has been the source of a lot of bugs.

But the second approach, using a text overlay, can do all of this with much simpler code and therefore we've removed the legacy approach for a two method approach: 1) use the placeholder when possible, unless hintOnFocus is true, or else 2) use a text overlay.
Fixes invalid unit test.
Adds warning for a possible cause of a failing unit test dependent on how the test was run.
Fixes up unit test and adds specific check for `hintOnFocus` being set to false.