Fixed RPL warnings.

There were a few variables that were set but never used, and it's time
to get those out so I don't have to ignore all the warnings.
Fixed tabs and whitespace.

Someone edited a lot of files with a text editor that, for whatever
reason that is unclear to me, doesn't change its tab settings to the
obvious tab settings of the document being edited. The person then used
8 character wide tabs when 8 spaces should have used, and an intelligent
editor makes it look terrible.
Created README

Added a little bit of info about RPL.
Add support to motelist for shimmer devices

Check for the FTDI FT2232 chip on the Shimmer docks and Span, as well as the FTDI FT232 on other devices
Merge pull request #183 from lab11/rpl-no-warning

Removed Compiler Warnings from RPL Stack
Merge pull request #193 from mikehealy/motelist

Add support to motelist for shimmer devices
Updated gitignore for cygwin

Other files are created on windows.
Merge pull request #194 from lab11/gitignore-tools

Updated gitignore for cygwin
Rename the unhelpful '.platform' file to 'platform'

Having the platform configuration file be a hidden file is one of the
most tragic and newbie-unfriendly decisions ever made by TinyOS. It
contains a fair bit of magic that is remarkably hard to find if you
aren't familiar with TinyOS. Worse yet, the error message if it is
missing used to give no indication whatsoever about what was wrong or
that a mystery hidden file should even exist. The old error message
produced after temporarily renaming epic's .platform file was:

    mkdir -p build/epic
        compiling BlinkAppC to a epic binary
    ncc -o build/epic/main.exe  -Os -I/home/ppannuto/code/shed/tinyos/tos/platforms/epic/chips/cc2520 -fnesc-separator=__ -Wall -Wshadow -Wnesc-all -target=epic -fnesc-cfile=build/epic/app.c -board= -DDEFINED_TOS_AM_GROUP=0x22 -DIDENT_APPNAME=\"BlinkAppC\" -DIDENT_USERNAME=\"ppannuto\" -DIDENT_HOSTNAME=\"pfet-vm-fedora\" -DIDENT_USERHASH=0x86e1c0ccL -DIDENT_TIMESTAMP=0x517ef83bL -DIDENT_UIDHASH=0xc3c958e6L  BlinkAppC.nc -lm
    Unknown target epic
    Known targets for TinyOS directory /home/ppannuto/code/tinyos-main/tos
    and the specified include directories are:
    mulle btnode3 eyesIFXv1 eyesIFXv2 mica2dot intelmote2 null shimmer2 tinynode shimmer2r span iris mica2 sam3u_ek ucmini telosa micaz shimmer telosb sam3s_ek z1
    make: *** [exe0] Error 2

The new error message helpfully informs the user that the needed
'platform' file is missing and also points to other directories that
have examples of proper platform files:

    Missing platform file for target epic
    For the TinyOS directory /home/ppannuto/code/tinyos-main/tos
    the following targets have valid platform files:
      btnode3 eyesIFXv1 eyesIFXv2 intelmote2 iris mica2 mica2dot micaz mulle null sam3s_ek sam3u_ek shimmer shimmer2 shimmer2r span telosa telosb tinynode ucmini z1
Apparently .sensor is a thing too
Also should to pick up .default-platform

Though it doesn't look like anyone's using it besides the root