High-Speed-Mode TCP Implementation

[Jmeyer1292]

Addressing issue #8, this PR adds the ability to interface with the Keyence using the asynchronous "high-speed" mode in which a separate tcp connection is used to constantly stream new profile data.

This PR contains the following:

1. A new class, keyence::HighSpeedTcpClient that can be started and stopped.
2. Starting the high speed connection requires the user to provide a callback function.
3. New synchronous commands that enable the high speed mode
4. Test/example program demonstrating the usage of the high speed mode both using the new interface and through making raw message calls.

This PR introduces the following new dependencies:

1. Boost including Boost-System and Boost-Thread libraries
2. C++11 - Required for usage of certain libsocket++ headers.

[Jmeyer1292]

@shaun-edwards Could you please either review or allow me rights to merge this PR?

[shaun-edwards]

Since you are using c++11 is there a reason you haven't used the std::atomic_flag?

[shaun-edwards]

Doxygen on public methods should be added.

[shaun-edwards]

Has the high speed interface been incorporated into a ROS node(s)?

[Jmeyer1292]

Thank you for looking at this. I will get on changes and documentation as quickly as possible.

[Levi-Armstrong]

@Jmeyer1292 Should this be closed?

[Jmeyer1292]

No it's still relevant. This stuff adds the support to reliably sample at 1khz. With the current interface we can only do about 200 Hz.