use of new without delete: clean up all (most) plugin class constructors and destructors.

looking at some of the code for instruments, there is often (SID for example) the use of _new_ without _delete_. This is a memory hole, maybe not a serious one, but none the less (C++ does not collect pointer referenced objects, it is not Java). I also noted that sometimes when _delete_ is called, it is called before rather than safely after detaching, from use by enclosing objects.

Start by auditing the instrument and plugin class constructors and destructors, including the SID example, for objects created with new but not released with delete. Check that deletion happens only after detaching from enclosing objects. Done means the affected classes have safe ownership and cleanup behavior, though the issue does not name specific files or tests.

Written by the indexing model from the issue text.