build: install and develspace interplay

[NikolausDemmel]

I just noticed these issues following a discussion in #64 (comment):

Calling catkin build --install after catkin build is broken for pure cmake packages. After the first call they will have been installed into the devel space and the second call will not install them to the source space.

Edit: I moved the second issue to #70

[wjwwood]

This is because catkin build does not --force-cmake when the --install option is added, this should be the case and is a scenario where catkin_make_isolated behaves correctly but catkin build does not.

This is related to #11 because these will both be accomplished by introducing some state-fullness to the workspace using a marker file, probably in the build space, with the settings used to build embedded into them. Then when ever a change is detected --force-cmake can be applied, which should cause the linking to update.

[NikolausDemmel]

@wjwwood: Your answer is addressing the first issue I raised, right? For that it makes much sense.

The second issue is happending when catkin build --install is invoked in a clean workspace (where catkin build has not been invoked before), so I'm not sure how --force-cmake might be relevant? (I should have opened two separate issues really...)

[wjwwood]

Oh, I didn't notice that, I'm not sure, I'd have to reproduce that and look more closely.

[NikolausDemmel]

I will open a separate ticket and edit this ticket, since it seems they are quite different issues.

[jbohren]

Since merging #249, installing is now fixed for pure CMake packages.