Update RobotEyeGrabber class to handle new packet format

[samontab]

Update RobotEyeGrabber to handle dynamic packet sizes, as well as a new header that includes time stamps.

[taketwo]

Hi, thanks for the contribution. Could you please format your patch according to the PCL style guide?

[samontab]

@taketwo I made the suggested changes.

PD: For some reason Travis keeps saying:
"clang: error: unable to execute command: Killed" when compiling with clang.
It seems to be a project setting issue instead of code because all the pull requests since 5 months ago are not being correctly built. This may be a bit off topic, but it affects all current pull requests.

[taketwo]

Thanks. Could you also squash the commits into one so that we have a clean history?

Yes, Travis fails almost every time in the recent months. This is certainly misleading, however so far we do not have a clean solution to the problem. Increasing the number of threads for compilation makes it likely that the server will choke, whereas reducing the number of threads makes it likely that we run out of 50 minutes limit...

[samontab]

@taketwo
Now there is only one commit for this pull request, and Travis behaved itself this time.

[taketwo]

Great! Thanks for the effort.