Refactor fix_shift_get_width in numeric.c
Refactor lshift in numeric.c
Refactor fix_to_f in numeric.c
Merge pull request #2066 from suzukaze/refactor-numeric2

Refactor numeric.c
resolve conflict
Merge branch 'master' of github.com:mruby/mruby
Move src/re.h to include/mruby/re.h .
Use mruby/re.h instead of duplicate definition.
convert exception message to string

fixes: mruby -e "p ArgumentError.new(1)"
get classname and concatenate ": " only once
various functions should have internal linkage
Merge pull request #2067 from take-cheeze/move_re_h

Move src/re.h to include/mruby/re.h .
Merge pull request #2068 from cremno/exc_inspect-convert-mesg-to-string

convert exception message to string
Merge pull request #2069 from cremno/static

various functions should have internal linkage
raises an ArgumentError when calling #call

based on a patch from @ksss; close #2070
Symbol#to_proc to support block call.

based on a patch from @ksss; close #2071
Add mrb_regexp_p to check whether mrb_value is Regexp.
Use mrb_regexp_p to check regexp.
Merge pull request #2072 from take-cheeze/mrb_regexp_p

Add mrb_regexp_p.
Implement String#index, fixes #2073