trac #16233: Removes the Graph Theory constructions page
trac #16361: OA(7,66), OA(7,68), OA(8,69), OA(7,74) and OA(8,76)
16424: test first if we have a triangular number at all
trac #16464: multiplicative cosets of finite field
trac #16461: difference families
trac #16461: reviewer comment 1 ++
trac #16461: more doc
trac #16461: merge #16464
trac #16461: adapt the implementation with #16464
trac #16461: reset finite_field_base.pyx to its previous state
trac #16461: always check the difference family
trac #16461: get rid of _nonzero_and_have_distinct_images
#9107: Enable nesting of a nested class into a nested class
#9107: Fix one cross reference in the documentation of a functorial construction
trac #16461: Merged with #16391
trac #16361: merge with #16461

Conflicts:
	src/sage/combinat/designs/orthogonal_arrays.py
#9107: fix a docstring (missing example and raw)
trac #16461: fix documentation
trac #16361: fix bug in IOA + better OA_from_PBD
trac #16361: merge updated #16461