MRB_INITIAL_HASH_SIZE : Make the initial hash size configurable.

C++ compatibility

Added mrbc support output to stdout

(Forgot a couple files)

Include array.h instead.

Remove unimplemented declarations.

Clean up hash.[ch]

Modify return value of mrbtest.

mrb_check_hash_type(): Remove as no implementation.

This is an improvement for CI, such as Travis.

Remove commented out code.

Modify class inheritance

Please append my name to AUTHORS.

* Rename some classes in test/t/class.rb to avoid name conflict.
* Add tests for mismatch fo superclass.

* Check mismatch of superclass.
* Check constant value whose name is specified as a class's name.

fix segmentation fault in Array#first

Protect deleted key and value from GC.

Modify ci->nregs.