Print some more info when initializing Context.

Then also don't display this information duplicated in magnum-info.

src/Magnum/Context.cpp

@@ -479,7 +479,10 @@ Context::Context(void functionLoader()) {
     CORRADE_ASSERT(!_current, "Context: Another context currently active", );
     _current = this;
 
-    /* Initialize state tracker */
+    /* Print some info and initialize state tracker (which also prints some
+       more info) */
+    Debug() << "Renderer:" << rendererString() << "by" << vendorString();
+    Debug() << "OpenGL version:" << versionString();
     _state = new Implementation::State(*this);
 
     /* Initialize functionality based on current OpenGL version and extensions */

src/Magnum/Platform/magnum-info.cpp

@@ -214,9 +214,6 @@ MagnumInfo::MagnumInfo(const Arguments& arguments): Platform::WindowlessApplicat
        place */
     createContext();
     Context* c = Context::current();
-    Debug() << "Vendor:" << c->vendorString();
-    Debug() << "Renderer:" << c->rendererString();
-    Debug() << "OpenGL version:" << c->version() << '(' + c->versionString() + ')';
 
     Debug() << "Context flags:";
     #ifndef MAGNUM_TARGET_GLES