Some wacky hacks to get @res suggestions for layouts

I think with some more hacking we can get proper values
for the elements (eg: wrap_content, etc.). It looks like
the first branch from ValuesContentAssist is not completing

Still not sure how Eclipse is doing it normally, since it
does *not* look like the LayoutContentAssist tries to do it
at *all*, and even ValuesContentAssist requires specific input
to do anything.