Cmake port

It got to be a bit more complex than I originally planned.
The terminal now supports (and requires) installing (make install).
The settings desktop file has been removed. Instead, there is a gsettings/dconf replacement, to make per user config easier. The keybindings file would either have to be ported to gsettings as well or be created by the app when a user runs it, or you just leave them the same for all users.
I also moved the file around to make things tidier, we have a cmake folder which hosts the vala related cmake modules, a src folder, which has all the vala files and a vapi folder which has the keybinder-3.0 vapi file. Downloading it manually will no longer be required, except for the library itself of course. (The problem previously was probably that you didn't rename your vapi to keybinder-3.0, so there were some troubles resolving the correct files).
In case you're wondering, the Config.vala.cmake file will be filled by cmake with the requested variables and then put as temporary vala file in the build dir for compilation.

For compilation, just do
mkdir build
cd build
cmake .. # you can add -DCMAKE_INSTALL_PREFIX=/usr, otherwise it will go to /usr/local/share/finalterm

Feel free to change or revert anything you don't like (or reject the entire thing), I'm open for questions or suggestions :)