Fix the spelling in a comment.
Cleaned up an obsolete #include game_preferences.hpp in preferences.hpp
Changed LoW's highest difficult level from hard to challenging
Fix a unit test that was invalidated shortly after its creation
Add extra tests and silence expected errors
Use BOOST_CHECK_EQUAL
Disable GUI2 new_widgets tests
Reorder alphabetically
Add missing GUI2 windows to test
Remove some debug output
Fix compilation with SDL 2.
Update some Doxygen comment.
Update formatting.
Refactor the ttexture image loading constructor.

The image to surface conversion part has been moved to its own helper
function. This will be used for a constructor using a SDL_Surface as
base.
updated Hungarian translation
Support for total conversions, so called "cores".
Merge branch 'mod'

Conflicts:
	changelog
	players_changelog
Fix compilation with cmake by including gui/dialogs/core_selection.cpp
Fix tab ---> spaces issue.
Fix tabs versus spaces issue.