function camelcase( str ) {
	str = replace( str, RE_SPECIAL, ' ' );
	str = replace( str, RE_WHITESPACE, ' ' );
	str = replace( str, RE_CAMEL, '$1 $2' );
	str = trim( str );
	return replace( str, RE_TO_CAMEL, replacer );
}
Converts a string to camel case.

@param {string} str - string to convert
@returns {string} camel-cased string

@example
var out = camelcase( 'foo bar' );
// returns 'fooBar'

@example
var out = camelcase( 'IS_MOBILE' );
// returns 'isMobile'

@example
var out = camelcase( 'Hello World!' );
// returns 'helloWorld'

@example
var out = camelcase( '--foo-bar--' );
// returns 'fooBar'