Refactor

[jwaataja]

Did a refactor. Made the following changes, may not be fully inclusive.

• Added license headers to code.
• Added a namespace and the correct namespace and header guards.
• Split the TypingTest class into the gui and non-gui components.
• Made a bunch of miscellaneous changes.
• Restyled some of the code. Case labels are no longer indented and it mostly follows the 80-column rule now.
• Added desktop file.
• Cleaned up CMakeLists.txt and some errors in it such as using the correct paths to resources and ensuring C++11 support.
• Documentation, both in the README and the code.
• Various bug fixes.