relax SVN archive

Bug fix for the minimise() user function.

The maximum number of iterations should be an integer. A float should not be accepted!

Wrote 6 unit tests for the rest of the minimise() user function keyword arguments.

Wrote a unit test to check the behaviour of minimise() user function with a bad keyword arg.

More tidying up of the unit test comments.

Removed an unnecessary comment.

Fixed the docstrings of the calc() and grid_search() arg unit tests.

The user functions were incorrectly named with 'minimisation.' prepended.

Simplified the non-keyword argument test of the minimise() user function.

Nested looping is not necessary to test all combinations.

Bug fix for the minimise() user function.

All arguments are now checked if they are strings.

Wrote a unit test for the arguments to the minimise() user function.

This is for the variable argument list for the minimisation algorithm and its options.

Added string tuples as a new data type for the user function argument unit tests.