relax SVN archive

Fixes for the PCS constant, as it is dependent on the indices i, j and c.

These are:
i, the experiment or alignment index,
j, the spin index,
c, the state index.

Added Boltzmann's constant to the physical_constants module.

Wrote the pcs_constant() function to calculate the pseudocontact shift constant.

Merged revisions 7128-7129 via svnmerge from
svn+ssh://bugman@.../svn/relax/1.3

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r7128 | bugman | 2008-08-10 00:02:18 +0200 (Sun, 10 Aug 2008) | 3 lines

Renamed the 'clean_temp' and 'clean' scons targets to 'clean' and 'clean_all' respectively.
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r7129 | bugman | 2008-08-10 13:50:55 +0200 (Sun, 10 Aug 2008) | 3 lines

The Monte Carlo error_analysis() function now uses the unimplemented specific model_loop() method.
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Fixed the atom_loop() call in __minimise_setup_pcs().

The structure identifier arg is now used by the atom_loop() method.

Implemented the generic_fns.pcs.centre() function.

Create the interface for the pcs.centre() user function.

Added the frq and temperature modules to the __all__ list.

Fixes for the frq.set() user function.