tidy up modules and readme for next npm release
add SDL key codes for minus and rsuper keys
removed old ui code and style
cleaned up build system cruft
updated readme
removed some unused code
code style tidyup
expose emscripten APIs
DRY up prepublish scripts a bit
Merge branch 'pcejs' of github.com:jsdf/pce into pcejs

Conflicts:
	commonjs/pcejs-atarist/package.json
	commonjs/pcejs-ibmpc/package.json
	commonjs/pcejs-macplus/package.json