WP 34S and 31S bugs and fixes

[pascal_meheut]

The convention I used is to follow the same for C code: _ to separate the words, lowercase.
For C++ methods, I used a common convention in object-oriented code: no _, first character in lower case, each word starting with an uppercase character.
Because increment_OnKeyTicks is a C++ method of QtKeyboard, it should be incrementOnKeyTicks (and update_OnKeyTicks should be updateOnKeyTicks).

I know I'm a bit anal about it but it helps code reading.