Fix calculating fullscreen resolution error metric. Closes #399.
Make object animation can set child and component's attribute animation.
LightAnimation sample now use ObjectAnimation in C++.
Fix typo[ci skip].
Insert GLSL version define before other defines if found from the shader code. Closes #398.
For Travis CI - reduce parallel build jobs to 2 for MinGW static lib.
This is necessary because the last two CI builds have failed for MinGW static library build due to insufficient memory during linking phase.

Also:
- Increase the number of build artifacts being kept in the SourceForge.net.
- Fixes #380 by skipping Mach-O binary (universal library) for iOS 64-bit build. The Urho3D lib in the build artifact will only contain 64-bit arch, 32-bit arch and iphonesimulator are excluded for now to reduce the build time.
For Travis CI - still do the packaging for iOS build no matter what.
Do not recreate sprite node in AnimatedSprite2D, Do not use dynamic index buffer bug in DrawableProxy2D.
Remove redundant default parameter.[ci skip]
Fix Transform2D argument.[ci skip]
Rename imp.png to imp_all.png, add texture parameters xml file.