Faster, better, but still not complete

The main changes in this release are
(1) faster implementations of many pieces, noting that (i) comparison is faster than subtraction, so straight-forward searches are faster than recursively iterating until we find solutions, and (ii) starting to use has tables to store previous results to avoid recomputing things again and again (this can be taken a lot further).
(2) Quite a bit of additional I/O, e.g., routines to read/write surreal numbers in a text (ascii) format similar to the way they are written in books, latex output, and output into DOT format of various graph versions of surreals.
(3) Changed several pieces to conform better to Julia standard style for, e.g., mathematical functions.

Also lots of other small changes and a few bug fixes for subtle problems that don't happen much of the time and a lot more tests.