Revert the ds, ts, fi and spec python object creation commits

Revert the ds, ts, fi and spec python object creation commits

- Hasty push-finger syndrom, while its not exactly plain wrong to
  do things this way, it doesn't really make sense for these types
  either. Python's own file object permits reinitialization though,
  so leaving rpm.fd() the way it is now.
- This reverts the following commits:
  d056df28c38e602d82b4f9b527c686037074e660
  3f77c3146da46a49f44b17fa66139fbe2dd9e45c
  7214b2e0a271b7a7b3df312c58593878cbf56504
  dc50fb2863c81159fb4cc8b25ce3862720c0cce5