relax SVN archive

Creation of the 'CHANGES' file.

Moved the committers file into the 'docs' directory.

Removed the bugs file (the bug tracker is all that is needed).

Renamed the release checklist file.

Updated the release checklist so that the directory 'relax-x.x.x' is included in the distributions
rather than just 'relax'.

Added two more OpenDX mapping tests to the test suite.

The parameters mapped in the new tests are {theta, phi, Da} and {tm, S2, te}.

Added a test for OpenDX mapping of the params {S2, te, Rex} through the user function dx.map().

The null device can now be opened instead of a file for writing by passing 'devnull' as the name.

Shifted the model-free results reading test of results.read() to the end of the list.

Added a test for setting the CSA value and bond length simultaneously to the test suite.