snapshot of 2018-04-07

Add KeyString class for conversion from a modifier and a key code to

a string and the opposite. Modify related code.

snapshot of 2011-08-30

snapshot of 2011-08-14

snapshot of 2011-08-07

snapshot of 2011-07-21

initial import

snapshot of 2011-07-17

snapshot of 2011-07-13

snapshot of 2011-07-02