fix size_t printf format
remove unused variable
remove compiler warnings for strtouint
remove variable length temp. array in ocra_parse_suite
remove unnecessary printf
add new strtouint_16 method, change session_length to uint16_t
removed unused vars
get rid of variable length arrays
fix loop counter signedness in challenge generation
don't error out on ALL warnings
remove unused var, add default switch branches
correctly initialize returned pointer