some if/elseif/endif tests
attempt to create a small makefile that uses all features of Make
up to date and working with best conditional directive code so far
add round trip capability to convert a Makefile instance into a string (Python expression), evaluate the python, then back into a Makefile
large nested if/else/endif test case
starting to parse multi-line macro so add a few tests; discovered a way to deduce the make version based on multi-line macros supporting "=" in the name
working ifdef/else/endif conditionals! fix several weird problems around trailing carriage returns; start adding multi-line macros