Merge branch 'release-0.4.1' into develop
add an overload of registerHandler
add an entry to the ChangeLog for the overload of registerHandler
Merge branch 'feature-easy-register' into develop
replace constexpr by inline for Hash with std::string
move updateEntity in child classes
add SingleSystem and CustomSystem
update ChangeLog for the systems changes
Merge branch 'feature-systems' into develop
bump version to 0.5.0
add the date for version 0.5.0 in the ChangeLog
Merge branch 'release-0.5.0'
initialize properly m_entity in SingleSystem
Merge branch 'hotfix-singlesystem-init'