preparation for more integer representations

n_Init_bigint: substituted by n_setMap/nMap
introduced cf->rep for different data representation
introduced several (experimental) integer variants
   via #define in libpolys/misc/auxiliary.h.in
bugfix in isSubModule
Merge pull request #614 from surface-smoothers/spielwiese

bugfix in isSubModule - brace typo
fix: format
fix: n_Lcm is not n_NormalizeHelper
the second typo in ring.lib . Gotcha\!
Merge pull request #616 from surface-smoothers/spielwiese

the second typo in ring.lib . Gotcha\!
fix: an example is an exmaple, nothing more
fix: degree test for subst(ideal/module/matrix...)
chg: added leftShift of CanonicalForms
chg: use leftShift in computation of cyclotomic polys
chg: modular resultant for small finite fields
chg: added pruning of alg extensions