Fix mistakes after previous merge and make it compile.
Rewrite the function interpolating between time stamps as it was
written after the original pull request was created. Add unit tests
for it.
I couldn't help myself and also changed some enums to enum classes and
did some renames.
SystemTimeStamp used to be an opaque class, as it was provided by
`system_{linux/other/windows}.h`. Because of this, code dealt in
SystemTimeStamp pointers, and getting the current timestamp required a
memory allocation. Now SystemTimeStamp is just a
`std::chrono::time_point`, we can make the code cleaner and faster by
just directly keeping SystemTimeStamp instead of pointers around.
* targets are now created in top-level build directory
* more things are now configured through CMake options
* changed debug build detection from NDEBUG to DEV_BUILD
* moved po and desktop directories
* moved last unit test out of src directory
* changed win32 implementation to QueryPerformaceTimer system function
* refactored system utils code
* proper tests for time utils and update event creation in application
* should fix issue #134
MrSimbax
immibis