Renamed some memebers __*__ -> OPT__\1
Revert "avoid empty procedures - keep Top-namespace clean (a start)" in order to keep stable interface

This reverts commit ba19a8a94da4931a7c4fb8ea6bc91256251c15ec.
+ minor changes : no export to Top
Minor cleanup in schreyer.lib / testing routines
Hiding all the implementation details (or adding the counting & extern declaration) 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}

also starting to fix bigint handling
Fix including "libpolys/" and removal of unnecessary header includes + minor cleanup
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!?
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)