further corrections (in my opinion) on subquotients
Merge branch 'public/combinat/interval-posets-15683' of git://trac.sagemath.org/sage into tamarinew
add reference to elliptic_j in j_invariant_qexp
trac 16224: make sure maxima_lib knows about bessel functions.
 Furthermore, max_to_sr and sr_to_max will now raise an error if they would
 overwrite an entry in a translation dictionary. This probably will make such
 corruptions due to mistranslations a little easier to diagnose.
 Finally, if you reraise an error in an except, it's better to do so by a bare
 "raise": that way the backtrace remains intact, which makes for better
 debugging.
Trac 10963: proofread Darij's changes
some improvements (i think), not done yet
some more edits
Trac 10963: proofread Darij's changes

In particular, removed an old warning in
Sets.ParentMethods._element_constructor_from_element_class which was
outdated by #14519.
Trac 10963: proofreading of Darij's doc change and minor further edits
Trac 10963: trivial doctest update w.r.t. #16125 (Implement method _an_element_ for Words)
Trac 10963: trivial doctest update w.r.t. merge of develop (matrix spaces now have one more method)
Trac 10963: trivial doctest update w.r.t. #15240 (Switch lattice polytopes to point collections)
Fixed issues reported on trac server comment 28 and 29.

1) _fast_eval does not use the parameter 'check'. Simply remove (from both _fast_eval functions)

2) @lazy_attribute function needs the documentation string + an example

2b) in the @lazy_attribute. Put the 'prime' and 'degree' inside the 'if' block so they are only computed if they are needed.

3) There is an extra blank line in _fast_eval for finite fields that can be removed

4) I'd like to see a few more doctests in _fast_eval. Maybe

a) Powerseries ring

b) quotient ring

max(abs(c.lift()) for c in coefficients)
Changed doctest for fast_eval.
trac 16224: make max_to_sr look in sage.symbolic.pynac.symbol_table['maxima']
for translations of operators. Since this is the central place where pynac
symbols register their conversion, this should lead to much more reliable
results.
clarifying Subobjects and Quotients interfaces
some questions
clarification of my clarification
more fixes; mostly done
Trac 10963: clarification^3 about subobjects