ProjectExplorer: Simplify BuildStepFactory

De-QObject-ify class, tr contexts are now the product's
context, which was the case in some BuildStepFactories already,
and is current state in {Run,DeployConfiguration}Factory.
One spurious object name removed.

De-virtualize canHandle(), it was never overloaded and is not
intended to be overloaded anymore.

Remove unused clone() function.

Change-Id: Iff7fba5f707505f868f94458084a18650535fa23
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/android/androiddeployqtstep.cpp

@@ -77,7 +77,7 @@ AndroidDeployQtStepFactory::AndroidDeployQtStepFactory()
     setSupportedStepList(ProjectExplorer::Constants::BUILDSTEPS_DEPLOY);
     setSupportedDeviceType(Constants::ANDROID_DEVICE_TYPE);
     setRepeatable(false);
-    setDisplayName(tr("Deploy to Android device or emulator"));
+    setDisplayName(AndroidDeployQtStep::tr("Deploy to Android device or emulator"));
 }
 
 // AndroidDeployQtStep

src/plugins/android/androiddeployqtstep.h

@@ -43,7 +43,6 @@ namespace Internal {
 
 class AndroidDeployQtStepFactory : public ProjectExplorer::BuildStepFactory
 {
-    Q_OBJECT
 public:
     AndroidDeployQtStepFactory();
 };

src/plugins/android/androidpackageinstallationstep.cpp

@@ -155,7 +155,7 @@ AndroidPackageInstallationFactory::AndroidPackageInstallationFactory()
     setSupportedStepList(ProjectExplorer::Constants::BUILDSTEPS_BUILD);
     setSupportedDeviceType(Android::Constants::ANDROID_DEVICE_TYPE);
     setRepeatable(false);
-    setDisplayName(tr("Deploy to device"));
+    setDisplayName(AndroidPackageInstallationStep::tr("Deploy to device"));
 }
 
 } // namespace Internal

src/plugins/android/androidpackageinstallationstep.h

@@ -68,8 +68,6 @@ private:
 
 class AndroidPackageInstallationFactory: public ProjectExplorer::BuildStepFactory
 {
-    Q_OBJECT
-
 public:
     AndroidPackageInstallationFactory();
 };