style
Merge pull request #288 from MatthieuDartiailh/scenegraph-fix-setup

Fixing setup (missing vispy.util.geometry)
Pure python PNG writer
Add @lcampagn 's make_png. No need to import from another library.
Just `from vispy.util import make_png`
FIX: Fix move button number
No need the alpha toggle in make_png
- Dimension can be obtained by data.shape[2]
- Check for dimension and data type
- Add alpha toggle to _screenshot
Improve readability
Flakify
Merge pull request #302 from lcampagn/scenegraph_update

Scenegraph update
Update docstrings, add more information.
Update docstrings for screenshot and read_pixels
FIX: Return original button
STY: Fix docstring [ci skip]
FIX: Fix first dt
Merge pull request #305 from Eric89GXL/fix-timer-dt

FIX: Fix first dt
FIX: None for .button
Add test for make_png
Save random RGBA and RGB arrays onto disk as PNGs using `make_png()`.
Read them back with an image library and check whether the array saved
is equal to the array read.
Merge pull request #304 from Eric89GXL/fix-move

FIX: Fix move button number
Cleaned up the activation pattern for gloo objects.

Basically, GLObject only provides _activate, and all objects now keep
track of _need_something, which they then "do" in the _activate method.
This may add a wee bit more code in some classes, but now at least it
is very clear what happens. This was especially problematic for the
Program class.
Clean the activation process of gloo objects

Basically, GLObject only provides _activate, and all objects now keep
track of _need_something, which they then "do" in the _activate method.
This may add a wee bit more code in some classes, but now at least it
is very clear what happens. This was especially problematic for the
Program class.
small fix for last commit