Replaced all xt-* calls with their xtensa-lx106-elf-* equivalents

so we don't have to create symlinks (assume windows has the xtensa* files?)

Removed an extra call to objdump from gen_misc_plus.sh that's not in gen_misc_plus.bat - seems to make the upgrade files, but the directory never gets created so it doesn't work anyway.

Added a "make install" routine borrowed from nodelua that generates the flash file and uploads using esptool.py (needs to be in your $PATH)