add %properties to argument list of the Box creator
added an obscure ->valueInFrame method; avoided perlcritic's 'undefined sort after return'
more care about array represented XML and libxml; make missing idref a non-Fatal (semi-recoverable) Error; check for XMRef in more places, especially trailing punctuation
when doing accents, don't assume that the base node has a role attribute
reworked \over,\choose, etal to get the proper mathstyle in both the numerator and denominator; also make \choose etal generate an XMDual; redefine \mathchoice so that it defers the choice until absorbtion time (which is more like TeX)
reworked \binom, etal, as well as \genfrac to generate XMDUals (when necessary)
reworked \cfrac to use the generalized \over macro; fixed \tag; added resource to amsart stylesheet (which should be close)
make ltx:bibliography autoclose, since there can be bare \refs
updated tests with \choose and \genfrac