Add tidump command for TI-83+ Series rom dumping

Squashed commit of the following:

commit 70602262795b5e5eea49802c84391db79ce1bd9f
Author: Jon Sturm <jonimoose@gmail.com>
Date:   Wed May 8 23:45:28 2013 -0500

    tidump: remove calc_73.c as it is no longer needed

    Missed in the last cleanup commit.

    Signed-off-by: Jon Sturm <jonimoose@gmail.com>

commit 806c3d8395e8e6b41516ae0a59c7b467a29ecf0c
Author: Jon Sturm <jonimoose@gmail.com>
Date:   Thu Apr 4 02:15:29 2013 -0500

    tidump: Clean up formatting and move to using the newly exported cmd73.h

    Also adds TI-84 Plus CSE support and makes things a bit more robust by actually
    checking return codes of functions for failure. Doesn't yet attempt to
    retry failed pages, it seems the silverlink gets confused when you do so.

    Will need further cleanup before merging with master.

    TODO: Either remove or allow toggling of ram dumps and perhaps add a parameter
    to only dump single pages for debugging or testing.

commit f7b12b6fee3cff3e23d87e29148cbcdfb65ad67a
Author: Jon Sturm <jonimoose@gmail.com>
Date:   Tue Apr 10 21:04:45 2012 -0500

    Hack in direct memory dumping.

    Will need to clean up and patch libticalcs so that I don't need to
    duplicate its internal functions here just for it to work. As well
    as remove the files taken from libticalcs once those functions are
    exported.

commit de4d3bf4bf2c671c8c334a5804c8fae6f979f114
Author: Jon Sturm <jonimoose@gmail.com>
Date:   Tue Apr 10 20:14:59 2012 -0500

    Add missing part of the 89 case in ascii_to_key in tikey

    This fixes sending keypresses to the TI89T via cables other than
    the USB DirectLink.

    Reported on IRC by chronomex.

    Signed-off-by: Jon Sturm <jonimoose@gmail.com>

Signed-off-by: Jon Sturm <jonimoose@gmail.com>