Move `Kernel.local_variables` to core.
Add 'Raise in rescue' test to exception.
Merge pull request #2296 from take-cheeze/core_local_vars

Move `Kernel.local_variables` to core.
Merge branch 'add-exception-test' of https://github.com/yui-knk/mruby into yui-knk-add-exception-test
correct comment; ref #2297
update raise in ensure test
Merge branch 'master' of github.com:mruby/mruby
move prototype of mrb_format() from error.h to mruby.h; ref #2274
Merge pull request #2295 from ksss/module-initialize

Implement Module#initialize (15.2.2.4.31)
Support extension '.cc' in globbing.
Correct comment in exception test.
Merge pull request #2299 from take-cheeze/cc_ext

Support extension '.cc' in source code listing.
Merge pull request #2300 from yui-knk/fix-comment

Correct comment in exception test.
break in blocks cannot cross C function boundaries; fix #2298
direct invocation of module_eval; ref #2298
Check mrbc_context is null
direct invocation of instance_eval
Merge pull request #2301 from mimaki/fix-load-mrb-segv

mrb_load_irep_file() caused SEGV
Module#initialize set created object
for block argument