Add new stack versions

stack/2020052700/maxima/assessment.mac

stack/2020052700/maxima/assessment.texi

stack/2020052700/maxima/casanswertest.mac

stack/2020052700/maxima/elementary.mac

stack/2020052700/maxima/errortostring.lisp

stack/2020052700/maxima/expandfeedback.mac

stack/2020052700/maxima/experimental.mac

stack/2020052700/maxima/inequalities.mac

stack/2020052700/maxima/intervals.mac

stack/2020052700/maxima/noun_arith.lisp

stack/2020052700/maxima/rtest_assessment_simpboth.mac

stack/2020052700/maxima/rtest_assessment_simpfalse.mac

stack/2020052700/maxima/rtest_assessment_simptrue.mac

stack/2020052700/maxima/rtest_elementary.mac

stack/2020052700/maxima/rtest_experimental.mac

stack/2020052700/maxima/rtest_inequalities.mac

stack/2020052700/maxima/rtest_intervals.mac

stack/2020052700/maxima/sandbox.wxm

stack/2020052700/maxima/stack_logic.lisp

stack/2020052700/maxima/stackmaxima.mac