Update utilities

[tomaszkax86]

This pull requests updates a variety of CMake and system utilities.

General list of changes:

• CSystemUtils is now a proper singleton; you're not meant to create multiple not fully initialized instances of it.
• Time utilities now use std::chrono::steady_clock instead of std::chrono::high_resolution_clock. This fixes a problem with negative time counter differences.
• Extracted compiler- and platform-specific configuration to separate CMake files. With this change it should be easier to port Colobot to other platforms and use different compilers.
• The game can be run in a different directory than the executable's directory. Helps run the game from build directory on multi-config build systems.
• Removed some of explicit compiler options. These options should be specified by the user or in CMake configuration profiles.
• Changed default build type to RelWithDebInfo. There's no point in using Debug by default.
• Moved error handling (signal handlers) to CSystemUtils
• Implemented stack trace in critical error messages for Windows

[hexagonrecursion]

• Time utilities now use std::chrono::steady_clock instead of std::chrono::high_resolution_clock. This fixes a problem with negative time counter differences.

• Does this fix Game crashes on autosave with "Fatal error: got negative system counter difference!" in logs #1518 and Crash to desktop due to negative system counter difference #1679 ?

[tomaszkax86]

• Does this fix Game crashes on autosave with "Fatal error: got negative system counter difference!" in logs #1518 and Crash to desktop due to negative system counter difference #1679 ?

It should. High-res clock isn't guaranteed to be monotonic and can be aliased to system clock. So it can go back in time when the system randomly chooses to update the system clock. Steady clock is guaranteed to be monotonic and never go back in time.