Make stretchy characters contribute to height/depth of the proper row (was using the wrong index).  Resolves issue #468.
Make sure mfenced delimiters are stretchy.  Resolves issue #475.
Bump version number for previous commit.
Rename mfenced() to fenced() since the mrow is not really equivalent (the mo's are forced to have stretchy=true).  Resolves Fred's concerns for issue #475 for now.
Merge remote-tracking branch 'dpvc/issue475' into v2.2-latest

Resolves issue #475
Merge remote-tracking branch 'dpvc/issue468' into v2.2-latest

Resolves issue #468
Repack and recombine previous commits