Merge Ruby r46039, r46051 and r46052

constify character property tables

* enc/jis/props.kwd: constify character property tables of JIS
  based encodings by perfect hash.
* enc/euc_jp.c, enc/shift_jis.c: use character property functions.
Fix coding style
Update README
Use numberof macro
Merge branch 'master' into ruby-2.x

Conflicts:
	Makefile.am
	Makefile.in
	enc/euc_jp.c
	enc/shift_jis.c