Proper hot reloading

[awto]

The partly changed functions can be reloaded with saving their state but the execution position and variable's positions are quite random (position based rather than better name based). So for currently executing functions, this works well only if something very small, e.g. constant is changed only.

To resolve this it could hash the function's effect frames (e.g. using SHA-1) rather than just the frame's number, so than reloading it is easier to identify the exact position, and also the number of frames will be reduced.