Use EasyMile's fork of lms1xx.

[esteve]

This PR replaces the lms1xx library with EasyMile's (https://github.com/EasyMile/lms1xx), the API is very similar, and includes the following improvements:

• support for timeouts
• fixes several underflow issues
• crossplatform compatibility (via Boost.asio, instead of the Sockets API)

I've added it as an external CMake project, but I don't know if it'd be better as a separate Bloom package released into ROS and have the LMS1xx ROS driver depend on it or just copying the source files into this repository.

One semi-drawback of using this library is that it depends on C++11. Kinetic added C++11 as a requirement for compilers, but Indigo is still at C++03. I'm not sure what the most viable path is, but I guess it'd mean creating a new branch for Kinetic and onwards.

[mikepurvis]

Thanks!

Given that this is a non-core package, I think I'd be fine to simply add the flag for c++11 in this package's build. If you only need language features and not the new standard library stuff, GCC 4.8.2 (Ubuntu Trusty) almost certainly has you covered: https://gcc.gnu.org/gcc-4.8/cxx0x_status.html

The status of bloom as far as submodules is still a bit uncertain (ros-infrastructure/bloom#217), but releasing the library separately and having to patch in the package.xml file is a pretty big pain too. Unless you feel strongly, I'd be inclined to just copy in the source and have a readme note in the parent directory explaining when and where it came from.

[esteve]

@mikepurvis sorry for the slow response. Yeah, I used CMake's ExternalProject_Add instead of git submodules because of bloom. In the worst case, I can just copy the library here, but I'd rather not duplicate the code to avoid keeping both in sync.

It seems that Travis is missing catkin_pkg, let me see if I can fix that and I'll submit another pull request:

https://travis-ci.org/clearpathrobotics/LMS1xx/jobs/260560497

...
-- Using Python nosetests: /usr/bin/nosetests-2.7
ImportError: "from catkin_pkg.package import parse_package" failed: No module named catkin_pkg.package
Make sure that you have installed "catkin_pkg", it is up to date and on the PYTHONPATH.
CMake Error at /opt/ros/indigo/share/catkin/cmake/safe_execute_process.cmake:11 (message):
  execute_process(/opt/python/2.7.13/bin/python
  "/opt/ros/indigo/share/catkin/cmake/parse_package_xml.py"
  "/opt/ros/indigo/share/catkin/cmake/../package.xml"
  "/home/travis/catkin_ws/build/catkin/catkin_generated/version/package.cmake")
  returned error code 1
Call Stack (most recent call first):
  /opt/ros/indigo/share/catkin/cmake/catkin_package_xml.cmake:63 (safe_execute_process)
  /opt/ros/indigo/share/catkin/cmake/all.cmake:151 (_catkin_package_xml)
  /opt/ros/indigo/share/catkin/cmake/catkinConfig.cmake:20 (include)
  CMakeLists.txt:52 (find_package)
-- Configuring incomplete, errors occurred!
See also "/home/travis/catkin_ws/build/CMakeFiles/CMakeOutput.log".
See also "/home/travis/catkin_ws/build/CMakeFiles/CMakeError.log".
Invoking "cmake" failed
The command "catkin_make" exited with 1.
...