Microplanning: various changes

- Allows a "possession" link to be deleted if the object can become a pronoun.
- Wrapping atoms in a custom container for better time weight and allows repeated sentences.
- Changed chunking option to be based on the number of sentence-formed links instead of number of nouns/verbs/adj/adv.  **(seems to be a better idea)**
- Misc bug fixes and documentation.

This should complete the "awkwardly working microplanner" phrase unless some new bugs/ideas come up.