fix #isMultibyte #274
fix #isMultibyte #isAscii
add #isVariableWidth,#isHalfWidth instead of #isMultibyte,#isAscii
fix #isVariableWidth,#isHalfWidth,#isFullWidth,#isAscii,#isMultibyte
Merge branch 'feature/multibyte' of github.com:tgfjt/validator.js into tgfjt-feature/multibyte

Conflicts:
	validator.min.js
Add new methods to the README, re #274