Add dependency to build gems list

Fix build tasks

remove mrb_str_each_line

Fixed mrbtest result numbers

Removed gem libraries in mrbc

add mrb_check_hash_type

Remove compiler warnings

Make conf.bins work for cross compiled deps as well as the host.

Host's mrbc file should be used when cross-compiling mrbtest.c

Added conf.bins for defining bulding binaries

Added s flag to ar command

Strict runtime error checking

Remove redundant null checks.