provide a more refined version for def-gm-method
move presentation output to mo-prepare, to support nested presentations
some code for formatting symbolic expressions (i.e. formulas)
migrate crude format output to the proper formula display
get rid of most format calls
add missing presentation type for integer-mod
translate some more format calls to put-result/formula
enrich integers with presentations, so pell solutions are just a few
clicks away
load formulas before continued-fractions
make implement-printer-method invokation more readable
define presentations before math-output-prepare