Py-predicate

- Added tee_p, to capture side effects (for example printing) in complex predicates
- Added a few more predicates to handle dictionaries
- Added ge_le_p, ge_lt_p, gt_le_p and gt_lt_p to capture ranges like 2 < x < 5.
- Added optimisation for above predicates
- Added methods to create values, given a predicate, make it either False or True (WIP)
- Documentation updates
- Added 2 tutorials

What's Changed

* 2 new lazy predicates: root_p and this_p
* is_range_p to check if a value is a range
* parser to convert string with named predicates to a predicate structure, for example "(p & q) | r"
* truthy and falsy predicates
* predicate to check string against a regex
* added is_list_of_p to check the contents of a list against a predicate
* added is_tuple_of_p to check the contents of a tuple against multiple predicates
* updated documentation
* cleanup

What's Changed
* Lazy predicates
* Improved test coverage
* More complete documentation of functions and classes
* Many more useful predicates
* More options to optimize predicates
* Option to generate truth tables from predicates