reformatted modrat error for easier filtering
reorganised handling of MODULUS/BIGPRIME etc for modular linear algebra, making it possible to vary the modulus
All modrat and lift functions now return a success flag and have no warning output
added chinese lifting for two moduli for smats
removed hard-wired 32-bit limit on number of bad primes in mwrank, replacing it with NTL_BITS_PER_LONG
Merge branch 'multimodular'