Fix two rule-reload memory leak issues

[martinhsv]

This PR commits two of three issues originally submitted in #2580.

[liudongmiao]

@martinhsv I suggest to avoid use:

if (transformations != NULL) { delete transformations; } 

It's confused to free memory of constructor argument.

In the similiar #2728, I use shared_ptr to avoid delete.

For virtual ~Rule, it's ok. I have explained other solutions too: #2728 (comment)

[martinhsv]

@liudongmiao ,

This way of deleting the transactions vector has some disadvantages, but it is that way in this PR because:

• that is how it was coded in the original PR, which this is replacing
• this way is consistent with how 'actions' was already being handled