PawnPlus v1.3

Additions:

• map_new and pool_new allow specifying the ordered state at creation.
• bool:stay parameter for iter_erase specifying the iterator shouldn't move to the next element. Usable in loops. New iter_empty function, also usable via operator!.
• var_iter accepts count like in iter_repeat. handle_iter added.
• Task-related optimizations.

Fixes:

• Cloning a pool doesn't reassign the indices.
• Cloning a map or a pool preserves its ordered state.
• Deep clear of some containers doesn't delete them anymore.