Fixed compilation.

Broken in b6d87291ed899b8530e4cbd036705a1339505fa6 where Utility/Debug.h
include was removed, but never tested. Added forward declarations for
Debug, Warning and Error classes (they are used in e.g. operator<<
declarations), added missing include on places which needed that.
Utility: added support for multi-line values in Configuration.

Inspired by Python, multi-line values start and end with """ alone on
the line (first and last line break is ignored).
Utility: return UTF-32 as char32_t.
Utility: added Unicode::utf32().
Utility: ability to save Configuration to specific file or stream.
Utility: reworked Configuration.

Axed many unused or unmaintainable features (unique names, auto name
creation, getting values via pointer...). Simplified and refactored the
code and API, updated unit tests.
Utility: fixed crash when compiling *no* resource files.
Utility: minor cleanup and documentation improvement.
Utility: minor test cleanup.

Leftovers from Kompas (yay!).
Utility: print iterables to Debug surrounded with {}, not [].

Visual compatibility with C++11's initializer lists.
Utility: support for printing UTF-32 chars and strings to Debug output.
Utility: support for uppercase numeric values in configuration.

Replaces support for color printing, as that is not really useful.
Utility: support for saving char32_t to configuration.

Saved as uppercase hexadecimal value.