Fix a warning happens on MRB_INT64 enabled.
Remove memmove(). Use value_move() instead.

value_move() is type-safer than memmove().

And may be faster on some targets.
(If it makes slow on your target,
rewrite to call memset(s1, s2, sizeof(mrb_value)*n)
in value_move().)
Removed unused expr
Merge pull request #1021 from monaka/pr-fix-warning-20130316

Fix a warning happens on MRB_INT64 enabled.
Merge pull request #1027 from masuidrive/remove_unused_if

Removed unused expr
Merge pull request #1026 from crimsonwoods/fix_bitfield_type

fix the type of bit field variable.
Merge pull request #1023 from monaka/pr-remove-memmove-from-vm.c

Remove memmove() in src/vm.c.
applying C++ patch from @monaka to support C++ bool type; close #1019
Merge branch 'master' of github.com:mruby/mruby