Remove obsolete build options and add a new -k option to bypass the initial cleaning phase and keep all build products of the previous run.

parse options before downloading nwjs binary (since some of the nwjs binary prep depends on whether we're building a dmg)

If compiling an OSX dmg, don't try to change permission on a file which doesn't exist for that platform

don't build wiringPi
don't run dpkg-architecture
remove reference to AppMain.tcl

fix tar_em_up.sh to store binaries in the main repo directory so that the gitlab ci can upload them as artifacts, and change the ci config to find them

* fix typo introduced into tar_em_up.sh
* remove flext and rtcmix from LIB_TARGETS
* selectively compile disis classes on Windows
* use Program Files (x86) for win64

moved cwiid and all disis libs except disis_munger to externals/disis, and removed linux-specific build instructions from tar_em_up.sh

begin porting the disis_* dirs to a single library in externals/, starting with disis_phasor~.c.  We're just using the most recent version of pdlibbuilder to do the heavy lifting.