Make mrows that are embellished operators properly include the elements other than the core when stretched.  Resolves issue #775.
Make fences use empty <mo> for blank delimiters so the result will not be an embellished operator.  Also resolves issue #775.
Take advantage of SVGdatStretched() rather than doing it by hand.
Allow comma-separated parameters in \mmlToken.  Resolves issue #906.
Check for undefined rather than false when deciding which attributes to allow for \mmlToken. Resolves issue #913.
Force displaystyle and scriptstyle to be included in toMathML output, since the defaults for these are complicated.  Resolves issue #912.
Have zoom box properly sized for tagged equations in NativeMML output.  Resolves issue #918.
Set the internal bounding box data properly for mpadded elements.  Resolves issue #917.
Make zoom box large enough for overlaps (e.g., when \llap, \rlap, or \smash are used) in SVG and HTML-CSS output. Can't do it effectively for NativeMML, since we don't know anything about overlaps in that case.  Resolves issue #835.
Merge branch 'issue775' into develop.  Issue #775.
Merge branch 'issue906' into develop.  Issue #906.
Merge branch 'issue913' into develop.  Issue #913.
Merge branch 'issue912' into develop.  Issue #912.
Merge branch 'issue918' into develop.  Issue #918.
Merge branch 'issue917' into develop.  Issue #917.
Merge branch 'issue835' into develop.  Issue #835.