improved error description when NTL is missing
Update cf_factor.cc

corrected spelling
chg: better assertions in factorize and deletion of SW_USE_NTL
chg: deleted SW_USE_NTL from cf_switches and misc_ip
chg: deleted SW_USE_NTL_GCD_*
memset 0 the input to the signal handler. valgrind wasn't happy
add assumes to prevent accidental use of mor than 8 StringSetS or too
many StringEndS'es
fix: minbase does not work for rings as coefficient
Merge pull request #537 from mmklee/factory_emsg

Factory emsg
fix: syntax of debug version (factory/cf_factor.cc)
fix typo
format
Fix wrong Latex in Doxygen description
Fixed Doxygen config template
Merge pull request #541 from mmklee/factory_emsg

fix typo
fix: segfault in > 2 Variable case
chg: use primitive psr gcd
chg: make modular resultant public
chg: use modular resultant in alg_factor
chg: use factory factorization in alg_factor