Added Operator Table generation script and README information

Also fixed the bugs you described by email. 

A synopsis of the test failures is included below.

```
1) =, \ddots, \coprod, \neq, \mid

Many tests fail due to the extra spacing around these characters as they are now correctly assigned to be Rel.

2) 
mfracz-comp30,prod1, sum2

These three tests change (there are a few more I neglect to list) because more operators are assigned to be Op. Such as sum, coprod etc. This change also changes the OMML output but I can't judge if that's sensible.

On inspection, all 198 failures fall into one of these two categories. 

The rest of the failures are the native tests. I omit them from my pull request.
```