Not deleting scopes

[epicleptico]

I faced an issue related to not destroying the scope related to the elements implementing new directives.

I think that i can make a plunkr about that but as basis when you have a directive inside the markup compiled and you change whole html text directive will be created again and will not be destroyed properly.

Related PR: #27

[ozairsajid]

@wytrych I am also facing the same problem. Can you help merge this PR? Thanks