(a) No action for an account, or on any simple or implied contract, or on any contract in writing, shall be brought but within six years after the right of action accrues, except as provided in subsection (b) of this section.

(b) Any person legally incapable of bringing any such action at the accruing of the right of action may sue at any time within three years after becoming legally capable of bringing the action.

(c) The provisions of this section shall not apply to actions upon judgments of any court of the United States or of any court of any state within the United States, or to any cause of action governed by article 2 of title 42a.