set main return value type explicitly in configure.ac
Merge branch 'fix.omalloc.configure.ac' of https://github.com/surface-smoothers/Sources into spielwiese

* 'fix.omalloc.configure.ac' of https://github.com/surface-smoothers/Sources:
  set main return value type explicitly in configure.ac
Moved Minor*, Cache* into kernel/
Moved minpoly.* into kernel/
add index entry Hensel
fix: allow indices like L[1..3][1]
chg: add chinrem(list(poly,,,),intvec/list) -> poly
chg: get rid of PrimePowerDomain
chg: deleted unused getmpi
removed isSqrFree
chg: keep exponents positive in convex dense (de)compression
chg: disable asserts
chg: use NTL/FLINT in *=
fix: segfault in ezgcd
chg: added test for segfault in ezgcd
fix: format
fix: make check test of factory without Singular
fix: standalone build of factory