src/hash.c:
- mrb_hash_(aget|aset|dup|delete): internal linkage
- remove documentation of methods which are not implemented (in here)
- remove #assoc; unused, not in ISO spec
- remove #rassoc: same, implementation is also wrong
hash-ext mrbgem:
- remove header "mruby/khash.h"
- remove mrb_hash_values_at (move code into hash_values_at, i: long -> int)
- less whitespace in gem_init function
- reduce compile time by a little bit (full-core: ~0.7s for me)
- thanks to 'include-what-you-use' for some help
- include Standard C header files before any other (coding style)