lib/is-html.js
function isIdent(c) {
	return c === COLON || c === DASH || isAlpha(c) || isNumber(c);
}
function isIdent(c) {
	return c === COLON || c === DASH || isAlpha(c) || isNumber(c);
}
Check if given character code belongs to HTML identifier
@param  {Number}  c
@return {Boolean}