[IZPACK-1116] "afterpack" listeners launched before applying <executable>, <parsable> and <updatefiles>

Currently, "afterpack" listeners launched before applying `<executable>`, `<parsable>` and `<updatefiles>` markers. This is non-intuitive and wrong.

Pre-parsed file with variables replaced and executable UNIX scripts cannot be used for instance in Ant actions this way.

Currently, unpacking a pack executes in this order:
- "beforepack" listeners
- "beforefile" listeners
- unpack file
- "afterfile" listener
- "afterpack" listeners.
- mark file "parsable"
- mark file "executable"
- clean up obsolete files according to `<updatefiles>`

Unpack packs should execute in the following new order:
- "beforepack" listeners
- "beforefile" listeners
- unpack file
- "afterfile" listener
- mark file "parsable"
- mark file "executable"
- clean up obsolete files according to `<updatefiles>`
- "afterpack" listeners.