feature: mac-style 105-key us keyboard layout

[DropD]

unifying input methods for osx and ubuntu

main issue: ~ key

• in all the us layouts on ubuntu the ~ is next to 1.
• in all layouts with correct ~ key, other important keys are off (£ on shift-3 etc).

minor issues:

These are only the ones i found so far.

• shift-§ should be degree