Refactor selection painting to fix highlighting of included views

Refactor selection painting to fix highlighting of included views

This changeset moves the painting of selection bounds and selection
hints out of the view rules and into the core IDE. The reason for this
is that the visual appearance of the selection shouldn't be up to each
rule; for one thing the selection highlight should be consistent and
not vary from view to view (and in fact there was only a single
implementation of the paint selection method among the view rules),
and for another the view rules are in theory sharable among IDEs
whereas the selection appearance is going to be IDE specific. There
was also painting of "hints" in the RelativeLayout; rather than having
the visual appearance of this dictated by the rule, this is also moved
into the IDE such that the rules only provide the hint text and the
hints are displayed by the IDE itself.

The above refactoring also fixes selection feedback for <include>'ed
views, which were not visually selectable because there was no
corresponding ViewRule, so nobody to paint selection. With these
changes selection painting is now independent of the rules.

Change-Id: I22dd926102128634a443b8bafb54d4764f1eda41