Improvements in doc on Schreyer orders
Added infrastructure so that e/unit-tests can test low level code in e dir.

This is not yet complete.  In order to not need to link in everything from d
and libfac, etc, some replacement code has been written (or will be, in the
next commit(s)).  The most important is that global 'new' and 'delete'
replacements from newdelete.cpp are NOT linked in.
unit tests part 1 complete.  Note that factory, frobby, and gmp CC and RR strings are not yet connected to unit tests.
added more tests for rings in e/unit-tests
Added more unit tests for basic coeff rings

Some tests still need more work, especially multiplication.
Promotion and lift are not yet tested.
small change to makefile
added more tests in e/unit-tests.  Fixed bugs found
Added more tests for top level rings (ZZ only in this commit)
Added assertion statements in Ring::syzygy routines, changing behavior slightly.

The second argument of this routine is not allowed to be 0.  Also,
unit tests for QQ, ZZ, ZZ/p, RRR, CCC have been added.
add -std=gnu++0x to unit test Makefile.

What compiler flag should we really use here?
We need to make sure that this works with cygwin, g++ 4.6.3 (and maybe
earlier ones too, for macosx support?)  The e directory compiles
fine with this flag (still lots and lots of warning messages).

Other changes are minimal here: add new test file which is not functional
yet, small changes to remove warning messages from g++.
rearranged files, but ring tower test has some memory problem
fixed dealloc of tower ring elements to allow non global malloc and free
renaming test files, part1.
renaming unit test files part 2
rearranging unit test files part 3.