port b64e49c8af118dc953e56967b83cd5fe65f4ebd3 from Pd-l2ork: made cleaner and likely more universal implementation of the bendin fix

add 83fbd4f32f3d2b77b5967e4e6025c3b748a189ae to Pd-l2ork: fixed bendin incorrect value (was range of 0-16383, now is -8192 to 8191)

port 9f5a265fc83fe268b23dcc0393d69a018ed497c5 from Pd-l2ork: Fix broken sys_alsa_putmidibyte() in order to make midiout work on Linux

another kludge-- bring back the code in makefile.mingw to compile everything in extra, and remove the expr~ external files

add x_preset.c and x_magicglass.c back to makefile.mingw-- they were accidentally removed in the big Vanilla backport

very stupid kludge just to get the code to compile on Windows-- this needs to get fixed by a more complete backport of Pd Vanilla's s_path.c code

port a031e3b64f725c8cb3274b5ef3ff0e27a36222f5 from Pd-l2ork: fixed parsing of @pd_extra and @pd_help names in filenames

port 9ab1b10476bca7e3998d5bf907296979dfc6e558 from Pd-l2ork: fixed regression where canvaslist was not properly stored

port d1e4c344d9a1022b1e960ca0a39c0232d68aad1d from Pd-l2ork: made initbang and closebang disabled if -noloadbang flag is used

port e814c4d586c52fe9a6a39a58947df1870e04e986 from Pd-l2ork: updated load/init/closebang to match the new spec

port 39a6b607659ebb5cafb0645d1c9046a07ac2922c from Pd-l2ork: added iemguts/ prefix to internal initbang and closebang to maintain compatibility with vanilla patches

port c6771297b6f03887034c5f121d3dbf701623ab87 from Pd-l2ork: the big Vanilla forward port won't compile without this commit