ToolChain: Refactor toolchain support

Refactor ToolChains in Qt Creator:

 * Allow for several toolchains of the same type
 * Be smarter wrt. guessing what kind of output a toolchain
   produces. This allows us to eventually handle e.g. embedded
   linux setups way better than before.
 * Be smarter wrt. guessing what kind of environment a Qt version
   needs.
 * Improve auto-detection of toolchains a bit
 * Decide on which debugger to use based on the kind of output
   produced by the compiler.
 * Add options page to configure toolchains
 * Remove toolchain related options from the Qt version dialog

Reviewed-by: dt

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.h

@@ -35,7 +35,7 @@
 #define CMAKEBUILDCONFIGURATION_H
 
 #include <projectexplorer/buildconfiguration.h>
-#include <projectexplorer/toolchaintype.h>
+#include <projectexplorer/abi.h>
 
 namespace ProjectExplorer {
 class ToolChain;
@@ -60,23 +60,14 @@ public:
 
     virtual QString buildDirectory() const;
 
-    ProjectExplorer::ToolChainType toolChainType() const;
-    ProjectExplorer::ToolChain *toolChain() const;
-
     void setBuildDirectory(const QString &buildDirectory);
 
-    QString msvcVersion() const;
-    void setMsvcVersion(const QString &msvcVersion);
-
     QVariantMap toMap() const;
 
     ProjectExplorer::IOutputParser *createOutputParser() const;
 
     Utils::Environment baseEnvironment() const;
 
-signals:
-    void msvcVersionChanged();
-
 protected:
     CMakeBuildConfiguration(CMakeTarget *parent, CMakeBuildConfiguration *source);
     virtual bool fromMap(const QVariantMap &map);