correct reported ACE binary version

statistics package was removed from ACE 4.

"options;" ACE command produces different output
in diffent state of the enumerator - perhaps, we can just
remove ACEBinaryVersion all together

reverting this commit will re-surface an ACE4-specific bug,
which makes ACEBinaryVersion hang if there is an active ACE session.

It all works, except that the option aceiputfile to write the ACE
input in an external file writes there the line

aceinputile: <file name>

- which ACE4 does not understand, but happily ignores.
So this is a minor quirk.

1) "a set of figures detailing the control flow in the
state machine that is at the core of the enumerator (see the
enum.c & enum0n.inc source files)."

2) example demonstrating new functionality of "pr;" command:
"The print table now takes two arguments, the beginning and ending
coset.  If the arguments are negative they mean (respectively) add
order/representative columns to the table and include coincident
coset rows.  To compact and standardise the coset table you need
to invoke st; before pr;."

* remove ps and pdf doc files for standalone ace

* restored ace3001 doc sources - merged a41 doc sources in them

* ace41 manual sources + mild changes to use includegraphics and xelatex

* adjust makefile for xelatex;  metapost to output *.eps

* add a reference on coset enum. for Th, and put in few numbers

* top level target for docs, gitignore more

* test CI for doc building

* upload ace41.pdf in CI, too

Co-authored-by: Max Horn <[email protected]>

Co-authored-by: Max Horn <[email protected]>

Co-authored-by: Max Horn <[email protected]>

Co-authored-by: Max Horn <[email protected]>