relax SVN archive

Added a few indecies to the development chapter of the manual.

A make rule called manual_nofetch has been also created to compile the manual without getting the
docstrings from the user functions.

Added a section on the make system and makefiles to the development chapter of the manual.

Spell check and formatting fixes to the relax development chapter of the manual.

Removal of the style file.

Added a chapter to the manual for coding and the development of relax.

The current contents of the chapter is the text from the file 'docs/style'.

Moved all the temporary manual files out of version control.

Compilation of the manual is now by 'make'.

To create the PDF version of the manual, type 'make manual' in the base directory, while to create
the HTML version, type 'make manual_html'. The two scripts 'docs/latex/compile' and
'docs/latex/create_html' have been shifted into the new makefile 'docs/latex/Makefile'.

Shifted the installation instructions from the text file docs/INSTALL to a chapter of the manual.

Changed a few of the to do items.

Relaxation curve fitting and Makefile changes.

A second Makefile within the 'maths_fns' directory has been created as a copy of the Makefile in the
base directory. The new Makefile contains the compilation rules for the maths_fns directory which
were located in the old file.

The files 'exp_fn.c' and 'exp_fn.h' have been renamed to 'relax_fit.c' and 'relax_fit.h'
respectively. This is so the old function names can contain the code for back calculating the
peak intensities from the given parameters, while the relax_fit code contains the setup function as
well as the functions func, dfunc, and d2func.

More minimisation code has been added to 'specific_fns/relax_fit.py'.