relax SVN archive

Fix for the pcs.read user function.

The problem was caught by the new Pcs.test_pcs_copy_different_spins system test. If the spin system
does not exist in the current data pipe, but data for it is present in the PCS file, the pcs.read
user function would terminate in a TypeError.

Created the Pcs.test_pcs_copy_different_spins system test.

This will be used to show a limitation of the pcs.copy user function in that it cannot copy data
between two data pipes with different molecule, residue, and spin sequences.

Small formatting change for the rdc.copy user function printouts.

Implemented the back_calc argument for the rdc.copy user function.

This allows the back-calculated RDCs to be additionally copied together with the real value and
error.

Modified the rdc.copy printout of RDCs to occur for each alignment ID.

Created the Rdc.test_rdc_copy_back_calc system test.

This will be used to implement the back_calc Boolean argument for the rdc.copy user function to
allow not only measured, but also back-calculated RDC values to be copied.

Modified the rdc.copy user function to printout all copied RDC values and errors.

Expanded the functionality of the rdc.copy user function.

The user function will now operate on two data pipes with different spin sequences. If the
interatomic data container is missing from the target data pipe, a warning is given. And if the
interatomic data container is not present in the source data pipe, nothing will be copied.

Some more modifications for the Rdc.test_rdc_copy_different_spins system test.

One of the interatomic data containers does not have RDC data, as it is not present in the original
data pipe, hence this is checked for. And the printouts have more formatting.

Big bug fix for the pipe_control.interatomic.interatomic_loop() function.

This was identified in the Rdc.test_rdc_copy_different_spins system test. The problem was that the
pipe argument was being ignored when looking up the spin containers. Hence if the pipe being worked
on was not the current data pipe, and the spin sequences were not identical, the function would
fail. This mainly affects the rdc.copy user function.