mcp2515: Initial implementation; C; C++

The mcp2515 is a CAN bus controller.  It was developed using the Seeed
CAN bus shield.

Signed-off-by: Jon Trulson <jtrulson@ics.com>

src/mcp2515/license.txt

@@ -0,0 +1,51 @@
+The table of CNF1-3 valuses used to set the CAN bus baudrate were
+taken from the Seeed studio code at:
+
+https://github.com/Seeed-Studio/CAN_BUS_Shield/
+
+/*
+  mcp_can.cpp
+  2012 Copyright (c) Seeed Technology Inc.  All right reserved.
+
+  Author:Loovee
+  2014-1-16
+
+  Contributor:
+
+  Cory J. Fowler
+  Latonita
+  Woodward1
+  Mehtajaghvi
+  BykeBlast
+  TheRo0T
+  Tsipizic
+  ralfEdmund
+  Nathancheek
+  BlueAndi
+  Adlerweb
+  Btetz
+  Hurvajs
+  xboxpro1
+
+  The MIT License (MIT)
+
+  Copyright (c) 2013 Seeed Technology Inc.
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
+*/