Aliases wp_insert_category() with minimal args.

If you want to update only some fields of an existing category, call this
function with only the new values set inside $catarr.

function wp_update_category( $catarr ) {
	$cat_ID = (int) $catarr['cat_ID'];

	if ( isset( $catarr['category_parent'] ) && ( $cat_ID == $catarr['category_parent'] ) ) {
		return false;
	}

	// First, get all of the original fields.
	$category = get_term( $cat_ID, 'category', ARRAY_A );
	_make_cat_compat( $category );

	// Escape data pulled from DB.
	$category = wp_slash( $category );

	// Merge old and new fields with new fields overwriting old ones.
	$catarr = array_merge( $category, $catarr );

	return wp_insert_category( $catarr );
}