Bugfixes in StaticLayout.

Bug 3422121

With ellipsize, lines starting with a very long word that does not
fit inside the width were simply ignored. Cut the long word instead.

start - widthStart index offset shift in BiDi.

The original ellipsize-end patch that added '...' after the last
word on end-ellipsized lines has been punted in favor of a true
ellipsize support in I.

I believe the StaticLayout calculateEllipsise is a no-op since textwidth <= avail
by construction: fitWidth and okwidth are < outerWidth. The only exception is the
paraEnd != here case in generate (when not a single character fits in width).
This case is exercised by StaticLayoutTest in cts (width of 8 pixels) and revealed
an offset error in widstart.

All in all, it looks like this code was probably never really tested. I tried some
typical text configuration to make sure these changes improved the situation.

Change-Id: Ibee410bd7db453abf93e10e8beb844eae998922c