Use pluginlib to reenable displays panel and load basic plugins

[wjwwood]

This pr does a bunch of stuff:

• sets up the rviz_default_plugins package
• uses the new ros2 branch for pluginlib:
  • https://github.com/ros/pluginlib/tree/ros2
• finishes migrating files that used pluginlib and that were skipped over in previous refactorings
• reeanbled the displays plugin
• changed some of the libraries to SHARED and changed other linking settings to address issue with multiple Ogre instances due to multiple copies of the Ogre static libraries
• routes logging of the application through the new ros logging infrastructure (fixes [rviz_rendering] Unnecessary information in ogre log messages #62, or at least works around it)
• migrates move tool and orbit view controller to rviz_default_plugins

What I still need to do:

• add pluginlib to instructions in readme
• (re) migrate a few of the display plugins, at least grid
• do an uncrustify and cpplint pass
• test on
  • Linux
  • Windows (disabled for now 😢)
• run tests
• update instructions or fix CMake to make it build on Linux
• resolve issues with filesystem experimental on Linux (linking and API issues)
• figure out what is wrong with the orbit view controller

This still doesn't get a display panel to show at first, that needs the configuration loading to be fixed, but you can add one from the add panel dialog.

I also need to test out the add display by topic more, since I just ported it without trying it out (just made it compile).

[greimela-si]

Nice work!

I built the branch on Ubuntu 16.04, here are some findings:

• The default tinyxml2 APT package libtinyxml2-dev is not sufficient for CMake builds, as it does not provide a TinyXML2Config.cmake. I had to add the tinyxml2 repo to the rviz workspace and build it from source.
• When building tinyxml2 from source it creates a tinyxml2Config.cmake (lowercase), but the build expects a TinyXML2Config.cmake (uppercase). I had to replace the name in find_package in the pluginlibs CMakeLists.txt with the lowercase variant.
• When using the default GCC (5.4.0), has_include(<experimental/filesystem>) in the filesystem_helper returns true but the API seems to miss some methods (e.g. fs::path::parent_path()). So the fact that <experimental/filesystem> is available may not be enough to use it.
• both the displays panel and the view controller panel can be added fine
• the orbit view controller behaves strangely right now

[wjwwood]

I updated the OP with more todo check boxes based on your feedback. I'm going to try and get this done today, but I have some things to do this afternoon which might get in the way of that.

[jeising]

Maybe we could take up these three fixes and tests for next week, @greimela-si and @wjwwood? So they would not be part of this PR:

• (re) migrate the display plugins
• figure out what is wrong with the orbit view controller
• test out the add display by topic more

[wjwwood]

@jeising that's the plan, but currently I'm hung up on an issue with the Qt Automoc step, but only on windows. I've spent the better part of a day on this one thing and haven't found a workaround just yet. I wanted it to be at least compiling before pushing this for merge (and then subsequently opening issues for the other problems).

I'll push what I have shortly and describe the problem before picking up on it again.

[greimela-si]

Some more findings:

• The resource_retriever is currently missing in the readme.

On Ubuntu:

• The library libassimpd.4.so can't be found when starting rviz2_app.
  It works after adding install/opt/rviz_assimp_vendor/lib folder to the LD_LIBRARY_PATH.

On Windows:

• The assimp vendor package fails to build due to this issue: Microsoft Visual Studio 2017 Building Issue C2678 / C2088 assimp/assimp#1548

[greimela-si]

I fixed the orbit view controller in #129.