bug fix: the argument of '--sysroot' option should be followed '=' character.
bug fix: add new option '-mandroid' into CFLAGS and same options are applied into LDFLAGS.
refactoring
add a new feature to select the target architecture.
add a new feature to select the target Android platform.
more CFLAGS and LDFLAGS are specified automatically.
Fix indent in string.c
Fix typo
return value from mrb_gc_arena_save() is int
restore arena after mrb_define_method()
Merge branch 'master' of github.com:mruby/mruby
Merge pull request #978 from carsonmcdonald/timetypofix

Fix typo
Merge pull request #976 from kano4/dev

Fix indent in string.c
fix inspect method
Merge pull request #981 from iij/pr-fix-inspect

fix inspect method
Rename STR_BUF_MIN_SIZE to MRB_STR_BUF_MIN_SIZE. Make it configurable.
Fix indents.
Remove mrb_str_new2(). Use mrb_str_new_cstr() instead.
 Make mrb_str_new_cstr() accept NULL pointer. It generates 0byte strings by NULL pointer.
Remove mrb_str_sublen() as it is not used.
Remove str_alloc(). Use mrb_obj_alloc_string instead.