Added enum helper template<typename E> toIntegral(E e) in steeltypes for cleaner loops, and updated relevant parts.
Minor updates
Fixed missing call to dispatchSelectionChangedEvent() after deleting the selection
Added checkboxes for logging signals
Updated doc
Memory leaks fixes with valgrind --tool=memcheck --leak-check=yes:

Before:
==19995== LEAK SUMMARY:
==19995==    definitely lost: 26,736 bytes in 34 blocks
==19995==    indirectly lost: 1,056,532 bytes in 64 blocks
==19995==      possibly lost: 3,325,395 bytes in 1,656 blocks
==19995==    still reachable: 1,487,013 bytes in 2,283 blocks
==19995== ERROR SUMMARY: 646 errors from 644 contexts (suppressed: 2 from 2)

After:
==18343== LEAK SUMMARY:
==18343==    definitely lost: 12,096 bytes in 3 blocks
==18343==    indirectly lost: 82,692 bytes in 152 blocks
==18343==      possibly lost: 2,189,979 bytes in 1,502 blocks
==18343==    still reachable: 434,337 bytes in 2,282 blocks
ERROR SUMMARY: 474 errors from 471 contexts (suppressed: 2 from 2)