define and use print format macros for mrb_int

For portability: %ld can't be used to print a 64-bit mrb_int on
WIN(32|64) because long is 32-bit wide.
Make array.c and vm.c share value_move().
Add bitbucket git support.
Use mrb_str_cat() instead of mrb_str_cat2() as possible.
Rename API mrb_str_cat2() to mrb_str_cat_cstr(). This is for naming orthogonality. mrb_str_cat2() is also left for backward compatibility.
Set MRB_TT_MODULE to Module.
Add mruby-random mrbgem (no activation though)
Add double-quote
Merge pull request #1052 from matsumoto-r/add_mruby_random

Add mruby random
Merge pull request #1051 from monaka/pr-set-MRB_TT_MODULE-to-Module

Set MRB_TT_MODULE to Module.
Merge pull request #1050 from monaka/pr-cleanup-string.c-20130323

Clean up string.c
Merge pull request #1048 from monaka/pr-make-array.c-and-vm.c-share-value_move

Make array.c and vm.c share value_move().
Merge pull request #1049 from monaka/pr-bitbucket-git-support

Add bitbucket git support.
Add new API mrb_ptr_as_string().
Remove *printf() that have "%p" format as possible. Use tomrb_ptr_as_string() instead.
Use mrb_obj_classname() instead of _obj_classname(). They are complietely same.
Remove _obj_classname() as unused.
Merge pull request #1055 from monaka/pr-remove-_obj_classname

Remove _obj_classname()
Merge branch 'pr-add-mrb_ptr_as_string' of https://github.com/monaka/mruby into monaka-pr-add-mrb_ptr_as_string
rename mrb_ptr_as_string() to mrb_ptr_to_str()