[Qt-creator] Refactoring the CMake plugin

[Daniel Teske]

> 1) Registering new cmake instances / tools
> 
>      The idea is to provide a way for plugins to register their own
> cmake installation
>      and I introduced a class called CMakeManager that will own all
> registered installations.
>      Every registered cmake will be represented by a CMakeTool instance,
> that abstracts away
>      how a specific cmake is invoked.
> 
>      To register them I can see 2 ways:
> 
>      a) using factories:
>      Personally I like factories more, maybe the approach used by
>      the toolchains would fit here too (QList<CMakeTool*>
> Factory::autoDetect()).
>      That would also require a UI in the settings dialog where the user
> can manage the
>      available cmake tools and manually register them.
> 
>      b) provide a function called registerCMakeTool() in the

I'd like to see more than just a ubuntu sdk specific use case for this. As is, 
I don't see much value in that.

> CMakeManager that can
>      be called by plugins.
> 
> 2) Associating a cmake tool with a build
> 
>      Now that there is a way to have more than one possible cmake, there
> needs to
>      be a way to control which cmake is used when building/creating the
> project files.
> 
>      a) By linking it to a Kit
>          -> provide a CMakeKitInformation so the user can control which
> Kit uses which
>          cmake tool
> 
>      b) By linking it to a build configuration
>         -> a CMakeBuildConfiguration would either need to return a
> Core::Id specifying the
>         cmake tool it wants to use, or the CMakeTool instance itself, so
> the IDE can use it
>         to create the build files. The build configurations config
> widget then can provide a
>         way for the user to switch between the cmake installations
> available.

Like Tobias said, definitely in the kit.

> 3) Automatically running cmake in the background (Get rid of the "Run
> cmake" dialog)
> 
>      It would be nice if the user was not required to handle the cmake
> dialog
>      every time he wants to change the build settings, cmake arguments
> or wants to
>      switch between different build configurations.
> 
>      In my MR, a cmake run is automatically started every time the build
>      settings are changed and when opening a unconfigured project the
> project
>      configuration page is used. At first sight this is very similar to
> how qmake behaves and makes it easily
>      possible to switch between multiple build configurations without
> the need for running
>      the cmake dialog every time. But the difference of course is that
> there are files created when running cmake
>      and the user does probably not know about that.
>
>      --> A possible solution to this would be to open a dialog to change
> the build settings, but to
>      run cmake automatically when switching between build
> configurations. This would make the user more aware of what
>      is happening.
Right, that would work.

daniel