Added documentation
Added a simple union/struct combo for defining the message data from KVH
data. As currently implemented, would be HIGHLY dependent on the
endieness of the host system. We're probably going to have to change
this significantly with a bunch of compile-time checks against the
system (probably in a full class implementaiton) to seperate it from the
underlying system more.

#11
Added a simple union/struct combo for defining the message data from KVH
data. As currently implemented, would be HIGHLY dependent on the
endieness of the host system. We're probably going to have to change
this significantly with a bunch of compile-time checks against the
system (probably in a full class implementaiton) to seperate it from the
underlying system more.

#11
Merge branch 'development' of https://github.com/RIVeR-Lab/kvh into development

Conflicts:
	kvh_driver/include/kvh_driver/kvhmessage.h
Properly implemented the level field in the .cfg file so that we can
determine what fields have been changed. Added a series of callbacks in
KVHDriverNode that are fired off based on the value of level in the DR
request. Currently they're just shell stubs that output to rosconsole,
with the exception of drUpdateRateCB, which properly adjusts the output
frequency of the IMU filter.

#10