Upgrade to latest development tools
#2 Use UMD instead of amdefine to make library usable with browser globals as well
#2 Migrate from grunt-urequire to grunt-umd because
- I can't figure out how to export a global variable with grunt-urequire if neither Node nor AMD is detected
- grunt-urequire is probably overkill for my use case (grunt-umd is much less complex)