Better handling of spaces at ends of lines in StaticLayout.

Skipping spaces at ends of line used to be done only when ok != here
(a potential line break was found).

Moved this logic up one level to handle all cases.

Also moved maxLine test in the block that actually adds a new line.

Updated the unit tests accordingly.

Change-Id: Ib10bc838b1ffa5b8a60259ea4b622d9fecb2ec70