Description of problem:
The channel.software.syncErrata API method does not work correctly. It's current behavior is:
1) Update the details of the cloned errata to match their originals (fine)
2) Clone packages into the cloned channel that are:
  a) in the original channel
  b) delivered by an erratum that has a clone

The 2b portion is the problem. The behavior should be "2b: delivered by an erratum that has a clone in this cloned channel"

If you have multiple clones of the same channel this bug can cause the wrong packages to be imported into your cloned channel. This is especially problematic since spacewalk-clone-by-date now calls this method by default.

Version-Release number of selected component (if applicable):
2.1

How reproducible:
always

Steps to Reproduce:
1. Clone a channel with all errata with spacewalk-clone-by-date
2. Clone the original channel again with spacewalk-clone-by-date, this time with only some of the errata

Actual results:
The second clone contains all the packages that the original did.

Expected results:
The second clone should contain only packages relevant to the errata it contains.