Fix a (perhaps rare) case where multiple presses or releases could be

xor instead of 'if'

bugfix issue #43

Improvements for noise immunity. Closes #33.

Incorporate PR #39: Change several member functions to const & add some initial values.

Cleanup some cppcheck warnings.

Change architectures to "*" in library.properties.

Move code for simple functions to the .h file.

Add JC_Button to keywords file so that syntax highlighting works on #include statement. Closes #25.

Closes #22.

Add ToggleButton derived class.

Fix constructor initializer list order. Closes #14.

Typo in README file.

README and comments updated.

Refactor source code, update example sketches.