add assert_{includes,instance_of,kind_of,raises} methods.
Make OP_ASGN faster.

I think that `*=` and `/=` can be compiled to `OP_MUL` and `OP_DIV`.
add chipKitMax32 target example
remove user specific directory
Adjust stack position of NODE_RESCUE.
Add more tests for `begin` and `rescue`.
Merge pull request #883 from masamitsu-murase/modify_node_rescue_handling

Adjust stack position of NODE_RESCUE.
Merge branch 'pr-mrbtest-assert-ext' of https://github.com/iij/mruby into iij-pr-mrbtest-assert-ext
rename assert_includes to assert_include
remove assert_instance_of and assert_kind_of which might hinder duck typing
rename assert_raises to assert_raise
Merge pull request #882 from bovi/chipkit

chipKitMax32 target example
Merge pull request #881 from masamitsu-murase/make_op_assign_faster

Make OP_ASGN faster.
Add skip method for test
Merge pull request #885 from mattn/test_skip

Add skip method for test
Remove needless file
Pluggable Time class
Remove needless files
Simplify mrb_range_beg_len(). Don't use OTHER macro.
Merge pull request #892 from mattn/remove_needless_files

Remove needless files