relax SVN archive

Fix for the 64-bit Linux distribution file md5sum placement.

This is for http://www.nmr-relax.com/download.html.

Updated the log file for comparing different alignment tensor basis sets for align_tensor.svd changes.

Improved the printouts from the align_tensor.svd user function by including the basis set text.

Created a script and log file to demonstrate differences between alignment tensor basis sets.

This shows that the inter-tensor angles and condition numbers are dependent on the basis set used.

Created 6 unit tests for the lib.geometry.vectors.vector_angle_atan2() function.

Added 6 unit tests for the lib.geometry.vectors.vector_angle_acos() function.

These are similar to those of the vector_angle_normal() function but unsigned angles are checked
for.

Renamed vector_angle() to vector_angle_normal() in the lib.geometry.vectors module.

This is to standardise the naming as there are now the standard vector angle formula implemented as
the vector_angle_acos() and vector_angle_atan2() functions.

Missing import.

Implemented the lib.geometry.vectors.vector_angle_acos() function.

This is used to calculate the inter-vector angle using the arccos of the dot product formula. The
function has been introduced into the relax library as the calculation is repeated throughout relax.

Implemented the lib.geometry.vectors.vector_angle_atan2() function.

This is for calculating the inter-vector angle using the more numerically stable atan2() formula.