0.9.2 has the memory fixes and several documentation updates

 This version is a hotfix that get the control working properly again.
 Before the line that checked if sdl is available actually checked if
 for opencv. This broke the builds that used sdl2 without compiling the
 opencv code.
 Because of the size and the importance of this fix, this will be a
 new patch release version.

 THis commit changes the library version to 0.9.0 and the format
 version to 0.6.0. The new format version break compatibility
 which is caused by the new physics.

 There is also an update for the train_properties json
 format in this commit. This just explains the format changes in
 format 0.6.0.

the control subsystem was completely rewritten. The control class was moved to the control namespace and renamed to input_handler. In addition to that it is no longer a singleton, which makes the class even cleaner. The latest version of the simulator is required for this to work. These changes break the simulator.

  This commit cleans core/type up.
  libtrainsim::core::clamp is replaced by std::clamp
  libtrainsim::core::version now uses a tuple to store the data.
  This makes comparing two versions easier and cleans.
  The new compare operators are also tested in the unit tests.

formatVersion 0.5.0 added the videoFile as required argument to the Track.