GitLab

This removes the all hard dependencies to and from welcome screen,
except the one to the core plugin. More in detail:

- Add IWelcomePage to add a tab to the welcome screen
- Move tabs in the modules where they belong
- Enables QHelpManager to open help fullscreen and contextually
- "Getting Started" moves to Qt4ProjectManager
- Projects & Sessions (aka "Develop") moves to ProjectExplorer
- "Community" remains in the welcome plugin for simplicity

Not finished 100%

So now you can choose not to automatically build before running.
And you can chose to automatically save all files before building.
The options are global and the default is the same as before.

The common code for all makesteps i mainly tracking in which directories
we are currently building. And guessing the filename from that
information. And creating a buildparser from a name.

After all I don't need all that stuff in the cmakeplugin, all i needed
is now bundled in debugginghelper.h/cpp

QtOptionsPage now has its own page.

Hopefully i didn't miss a plugin.

The Debugger, cmake and Qt4 plugin all need it. More refactoring to it
coming.

Rerun cmake and reparse the file. Add new files to the tree, remove old
ones from th tree. Add/removing targets should also work.

will use it also in the debugger, and pulling it in from projectexplorer
just seems wrong.

Details:  This enables us to parse the build errors correctly.
          The makesteps of the qt4project and cmakeproject have some
          code dupliaction, which could be refactored. And the code
          to find out the correct build parser could probably also
          be done better, but we are now parsing the build output for
          cmake.

Details:  These classes replace a number of classes with differing
interfaces by just one class. The design isn't quite perfect, but a lot
better than what it used to be. Also moved the ToolChain classes to the
projectexplorerm so that eventually the cmake plugin can also use them.

Dependencies between projects can now be edited in the Projects mode.
You can simply check for each project the projects that it depends on,
and they will be built first. A message box pops up when you try to
create a circular dependency.

Could use some testing.