The install target of the subprojects is not executed when launching the ALL_BUILD target of the superbuild

[traversaro]

Spin off of https://github.com/robotology/ycm/issues/82#issuecomment-112800650

@traversaro wrote :

In *nix systems, the install target is executed everytime the "main" target is invoked.. in Windows (at least in Visual Studio 2010 and Visual Studio 2013) the install is launched only if the subproject is actually compiled. This is a major annoyance if for some reason the installation was not successful, because in the default configuration then the only way to install the subprojects is to open the subproject solution manually and install it.

@drdanz replied :

I think I understand the reason for this... IIRC there is a check for the build tool in ExternalProject, and the install step is added only if it is make. This is something that should probably be fixed in ExternalProject and it is worth investigating