Fix zoom box sizes for tagged equations in HTML-CSS and NativeMML output.  Issue #824.
Trap error reading cookies.  Resolves issue #821.
Remove fonts from default VARIANT values, which where causing -smallOP to no inherit the normal fonts; this caused \int in STIX (and other fonts) not to be found, and so default to unknown character bboxes.  Resolves issue #820.
Merge branch 'issue824' into v2.4-beta.  Issue #824.
Merge branch 'issue821' into v2.4-beta.  Issue 821.
Merge branch 'issue820' into v2.4-beta.  Issue #820.