relax SVN archive

Huge clean up of all unused imports in relax.

These were found using the find_unused_imports.py development script. A number of these changes
significantly decrease the possibilities of circular imports appearing in the future. And this also
makes the relax library more independent from the rest of relax.

Added the missing Bioinformatics to the bibtex file journal name aliases.

Removed the dependence on the relax 'dep_check' module from the lib.frame_order package.

This is for more independence of the relax library.

Clean up of many unused imports in the test suite directories.

The unused imports were found using the find_unused_imports.py development script.

Shifted the read_spin_data() and write_spin_data() functions from lib.io to lib.sequence.

Removed a number of unused imports from the user function definitions.

These unused user_function package imports were found using the find_unused_imports.py development
script.

Shifted the pipe_control.sequence.validate_sequence() function into the relax library.

For this, the new lib.sequence module has been created. This change is for better library
independence. A circular import with lib.io and lib.arg_check has also been resolved.

Shifted the Python 2 and 3 compatibility module 'compat' into the relax library.

Improvements to the test_library_independence.py development script.

This script for checking the independence of the relax library will now recursively import all
packages and modules in the library and report at the end a list of all failures.

Removal of all unused imports in the lib.dispersion package.