Hiding all the implementation details (or adding the counting) mostly by
moving internal declarations from private headers into corresponding source files

rm: Remove internal includes (hiding privates) + cleanup
chg: cleanup internal headers
fix the usage of internal implementation functions of coeffs from outside of libpolys/coeffs (or libpolys/polys/ext_fiels)
fix header includes for coeffs/AE*.{h,cc}
add: FIXME&TODO mark reused privates

also starting to fix bigint handling
Fix including "libpolys/" and removal of unnecessary header includes + minor cleanup
Fix slimgb (tgb*) to count the use of inline 'np[A-Z][a-z]*M' functions from modulop.h

CHG: internal (non-inline) np[A-Z][a-z]* calls replaced by corresponding inline wrapper n_[A-Z][a-z]*
Removed the definition of convFactoryNSingAN from clapconv.cc in favor of using n_convFactoryNSingN (=nlConvFactoryNSingN in this case)
Mark deprecated BIGINT handling + related bugs / side effects

FIXMEs: nlGMP -> n_MPZ. Check for side effects and nlMapGMP
Fix: bug in BIGINT deletion
Fix: a possible bug due to sideeffect!?
Note that n_CoeffRingQuot1 should replace numbercoeffs
Buggy cfSetMap in OPAE[Qp].cc :(

NOTE: npSetMap has nothing to do with Ae[Qp]!
Merge pull request #679 from malex984/numstat2

Further number/coeffs interface fixes (part2)