Clean up shader compiler error string on shader live reload to allow recovery. Closes #363.

Source/Engine/Graphics/Direct3D9/D3D9ShaderVariation.cpp

@@ -131,12 +131,13 @@ void ShaderVariation::Release()
         }
         
         object_ = 0;
-        compilerOutput_.Clear();
-        
-        for (unsigned i = 0; i < MAX_TEXTURE_UNITS; ++i)
-            useTextureUnit_[i] = false;
-        parameters_.Clear();
     }
+    
+    compilerOutput_.Clear();
+    
+    for (unsigned i = 0; i < MAX_TEXTURE_UNITS; ++i)
+        useTextureUnit_[i] = false;
+    parameters_.Clear();
 }
 
 void ShaderVariation::SetName(const String& name)

Source/Engine/Graphics/OpenGL/OGLShaderVariation.cpp

@@ -79,10 +79,10 @@ void ShaderVariation::Release()
         }
         
         object_ = 0;
-        compilerOutput_.Clear();
-        
         graphics_->CleanupShaderPrograms();
     }
+    
+    compilerOutput_.Clear();
 }
 
 bool ShaderVariation::Create()