function reSemVer() {
	return /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$/;
}
Returns a regular expression to match a semantic version string.

@returns {RegExp} regular expression

@example
var RE_SEMVER = reSemVer();
// returns <RegExp>

var bool = RE_SEMVER.test( '1.0.0' );
// returns true

bool = RE_SEMVER.test( '1.0.0-alpha.1' );
// returns true

bool = RE_SEMVER.test( 'abc' );
// returns false

bool = RE_SEMVER.test( '1.0.0-alpha.1+build.1' );
// returns true