Merge pull request #665 from dorkster/bugfixes

Fix stat_modifier_mode errors being printed when they shouldn't
Change Utils::calcDist to float instead of double
Remove SoundManager::calc_distance and use Utils::calcDist instead
Remove Enemy::getDistance, use Utils::calcDist instead
Merge pull request #666 from stefanbeller/unified_distances

Use Utils::calcDist for all distance calculations