Merge pull request #6 from dwtj/master

Merge ping fixes
Merge pull request #7 from dwtj/master

First draft implementation of `sentinel`.
Merge pull request #8 from dwtj/master

Merging David's bugfixing and sentinel implementation
Slight changes to OI functions
Added echo test
Updated documentation
Sonar and IR reading
Added details to oi move and description of dump
Fixed Alex's name and alphabetized
Implemented `send_mesg_test_mode()` in `command.c` in order to
test the `_watchman` in `sentinel`. Unfortunately, the watchman
doesn't seem to work, so I have disabled it for now.
Added to oi move
Merge https://github.com/aore/mars-rover into aore-master
Merge branch 'master' of git://github.com/asr1/mars-rover into aore-master

Conflicts:
	rover/mars-rover.cproj
	rover/src/control.c
Merge pull request #16 from asr1/master

Pulled Alex's handlers for IR and sonar reading requests
Revised `sonar_reading_handler()` to send response data correctly.
Added `ir_reading_handler()`, which is almost an exact copy of
`sonar_reading_handler()`.
`ir_reading_handler()` now actually reads from IR rather than sonar.
Consolidated `ir_reading_handler()` and `sonar_reading_handler()`
into `dist_reading_handler()`.
Merge pull request #3 from dwtj/master

4-24