Deprecation warnings

[chapulina]

According to the wiki page:

Migration: Since ROS Hydro, tf has been "deprecated" in favor of tf2. tf2 is an iteration on tf providing generally the same feature set more efficiently. ... tf will continue to be supported for through at least J Turtle.

How about adding deprecation warnings to all the code in this repo?

I'd also suggest adding a README file with a warning and a link to the new recommended packages.

[tfoote]

That warning on the wiki page comes from the package.xml in the root of the package:

geometry/tf/package.xml

Line 12 in f91b5ef

<p><b>Migration</b>: Since ROS Hydro, tf has been "deprecated" in favor of <a href = "http://wiki.ros.org/tf2">tf2</a>. tf2 is an iteration on tf providing generally the same feature set more efficiently. As well as adding a few new features.<br/>

We've been doing a soft deprecation since now it's only an API wrapper on the new implementation. Maintaining the wrapper isn't too much work and there's still a lot of code using it. Now that we're past J turtle we could start more actively deprecating it. Targeting N-Turtle for deprecation with lots of compiler warnings and removal in O turtle might make sense.

[mortenfyhn]

How about modifying the repo description or adding a readme file that clearly states that the geometry2 repo should be preferred? It's easy to arrive here from a web search, find a header file with some useful stuff, and start using for instance this repo's eigen_conversions instead of geometry2's tf2_eigen, and so on.