relax SVN archive

Removed some bad calls to status.exec_lock.release().

This commit may have to be reverted in the future. The problem is that the execution lock is not
being held when these calls are made. The calls were added as a kludge to handle certain situations
where the execution lock was not released. There may be cases were this behaviour is still needed.

The numpy include is no longer used for the compilation of the C modules.

Numpy is not used at all in the C modules, so this just adds an annoying dependency for those who
need to compile the module themselves.

The exponential C file now uses the exp() function from math.h rather than Python.h.

This file is independent from Python.

Spacing fixes.

Documentation improvements for the back_calc_I() function of the relax_fit C module.

Converted the Py_BuildValue() calls to PyFloat_FromDouble() in the relax_fit C module.

This doesn't change much.

Improved the Python and C documentation of the functions of the relax_fit C module.

Shifted the C array creation to the relax_fit C module header.

The params, values, sd, relax_times, and scaling_matrix C arrays are now declared and allocated in
the header file rather than using malloc() calls in the setup() function. This is to attempt to
remove a memory leak. The arrays are now of fixed length and reused for each setup() call. These,
as well as the other variables declared in the header are no longer declared in the functions.

Increased the maximum number of relaxation times for the relax_fit C module to 50.

Removed an unused declaration in the relax_fit C module setup() function.