fix window not being fullscreen when Config('graphics', 'fullscreen') is set to auto
Merge branch 'master' of github.com:kivy/kivy

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Merge branch 'master' of github.com:hansent/kivy
Merge branch 'master' of github.com:kivy/kivy
Merge branch 'master' of github.com:kivy/kivy
Merge branch 'master' of github.com:kivy/kivy
uix:Bubble introduce a `limit_to` property
uix:bubble add versionadded info for `limit_to`
custom vertex format.  using VertexFormat class, the attributes of vertices used in fbo can be configured.
Mesh vertex instruction has new property / kwarg fmt to specify vertex format for the mesh data.
transformations, add additional matrix functions usefull for 3D graphics.
new functions: transpose, pserspective, and look_at
also fixed view_clip for when perspective = 1
uix:textinput wrap_fix
add source property to shader to enable loading fragment and vertex shader from a singel file with --vertex (.*)-- / --fragment (.*)-- seperators
add matrix function to compute a normal matrix (inverse transpose, leaving angles the same)
fix bug in mesh, upload all vertices not just a quarter of them :P
add some new ContextInstruction usefull for 3D rendering:
  - PushState, ChangeState, PopState (like PushMatrix etc. but for any state/uniform)
  - ScaleXYZ (non uniform scale on all 3 axis)
  - UpdateNormalMatrix (set uniform 'normal_mat' based on current modelview_mat)
  - ApplyContextMatrix (multiply a current matrix by one from another matrix stack in context)
  - LoadIdentity (loads identity matrix)
  - all Matrixinstructions now als have 'stack' property to allow using multiple different kind of matrices.
add simple 3D rendering example
add versionadded and versionchanged doc strings
- load texture coordinates and normals correctly even if missing (default vectors with 0.0)
- added calculate_normals to MeshData class for calculating surface normals of mesh faces (not sure it works correctly)
use with context for readiong files in shader.pyx to ensure files get closed
Doc: update the link to the VM