Add args in Enumerator#inspect
add tests for FalseClass

reorder and add tests for 15.2.6.1
Pass gem's version information to compilers.
remove tests for unicode chars in regular expression literals.

mruby does not parse escape characters in a regular expression
literal (ref #2007).  It is parsed by the external mrbgem that
provides Regexp class, if any.  These tests should not be in
mruby core but in the mrbgem.
Always increment `total` field of `os_count_struct` in callback.
Check sum of `ObjectSpace.count_objects` values is twice of total objects count.
(Which is CRuby's behavior.)
Merge pull request #2020 from iij/pr-remove-unicode-escape-tests

remove tests for unicode chars in regular expression literals.
Merge pull request #2019 from monaka/pr-add-macro-for-mrbgem-version

Pass gem's version information to compilers.
Merge pull request #2018 from akuroda/pr_false_test

add tests for FalseClass
Merge pull request #2021 from take-cheeze/count_objects_total

Always increment `total` field of `os_count_struct` in callback.
Merge pull request #2017 from suzukaze/fix_enumerator.inspect

Add args in Enumerator#inspect
wrap args by parens
should have passed args to to_enum
Delete khash_mask macro.
And fix expression to more simple and readable.
Use kh_end instead to n_buckets
Merge pull request #2022 from ksss/khash-delete-khash_mask

Delete khash_mask macro
Merge pull request #2023 from ksss/khash-readable

Use kh_end instead to n_buckets
Hash#replace should copy default from original even when the default value of the original is not set
Merge branch 'master' of github.com:mruby/mruby
Merge branch 'master' into iij