support standard io stream
remove memory leaks in launcher/dshell.c
Merge pull request #16 from imasahiro/fix_memory_leak_at_launcher

Remove memory leaks in launcher/dshell.c
refactor makefile
improve completor
now can execute command without import
fix subproject revision
now support dshellrc
several fix
bug fix and improve completor
refactor builtin command
add some class for datashell