Allow pipe and exclamation point in attribute values

 * 97c45e848535185600f6d0fa8fe175f88786cd9b prevents exclamation points
   from being eaten as attribute names but was perhaps a bit overreaching.
   Only the attribute_preprocessor_text_line production is used in
   parsing names. Pipes were similarly affected.

 * Maintains the fix from that bug,

     {|
     ! Foo !! style="color: red" | Bar
     |}

 * And fixes the recent one reported,

     {| title="!=foo"
     |foo
     |}

 * Also changes unclosed single line attributes that end in a newline to
   parse with the _broken productions, which is both necessary here and
   seems more correct.

 * Removes preprocessor_text production as dead code.

 * Combines two tests with the newer html/(php|parsoid) syntax.

 * A little cleanup as well.

Change-Id: I493df53632f6baa9c7b2b01f5fd7f2e620b69f05