(a) Unless otherwise provided by the by-laws, regular meetings of the board may be held without notice if the time and place of such meetings are fixed by the by-laws or the board. Special meetings of the board shall be held upon notice to the directors.

(b) The by-laws may prescribe what shall constitute notice of meeting of the board. A notice, or waiver of notice, need not specify the purpose of any regular or special meeting of the board, unless required by the by-laws.

(c) Notice of a meeting need not be given to any director who submits a signed waiver of notice whether before or after the meeting, or who attends the meeting without protesting, prior thereto or at its commencement, the lack of notice to him.

(d) A majority of the directors present, whether or not a quorum is present, may adjourn any meeting to another time and place. If the by-laws so provide, notice of any adjournment of a meeting of the board to another time or place shall be given to the directors who were not present at the time of the adjournment and, unless such time and place are announced at the meeting, to the other directors.