DOC: Removed argument tuple unpacking in README.

lambda (x,y,z) : sqrt(x**2+y**2+z**2) is valid Python 2.x but not valid
Python3 (unfortunately). Removed offending line from README file.
BLD: Allow syntax highlighting of LONG_DESCRIPTION in setup.

Previously, the code snippet in the README file (and hence in the
LONG_DESCRIPTION keyword) was just an rst literal block. Now it's
a .. code::python block.

The README file is now automatically generated from the LONG_DESCRIPTION
keyword, rather than the converse.

Because the README file has to be parsed by
Github and other programs that don't necessarily understand non-standard
extensions to rst, the substitution ".. code::python" -> "::" is made
when generating the Makefile.
BLD: New README file automatically at setup.

Moved code to generate new README file into its own function.
Merge branch 'color_ld'

Syntax highlighting in long description.
DOC: Reduced number of contours in importance figure.

This reduces the size of the generated pdf figure considerably.
BLD: Pruned source distribution.

Removed generated *.aux and *.log files generated during compilation of
tex files. Removed generated test_readme.pdf that gave analytical values
for the tests.
Merge branch 'source_size'

Reduce size of source distribution.