Merge lp://qastaging/~hikiko/compiz/compiz.glvector-fixes into lp://qastaging/compiz/0.9.12

Change in GLVector implementation

Bug:
The GLVectors of compiz are 4 dimensional (x, y, z, w): https://en.wikipedia.org/wiki/Homogeneous_coordinates The w coordinate should be initialized to 1 and be preserved when we perform vector operations (additions/multiplications etc) otherwise the transformations won't be correct. For example: if we add or subtract the w values during two vectors addition we might have unexpected projections when the new w value is > 1 or divisions by 0 (when the new w is 0) because opengl divides the x,y,z values by w.

Solution:
- Changed the constructors to initialize w to 1 and not to 0 by default.
- Fixed the vector operations to use the x, y, z coordinates only.
- Fixed the existing constructors in plugins to initialize w to 1 and not to 0.

Change in GLVector implementation

Bug:
The GLVectors of compiz are 4 dimensional (x, y, z, w): https://en.wikipedia.org/wiki/Homogeneous_coordinates The w coordinate should be initialized to 1 and be preserved when we perform vector operations (additions/multiplications etc) otherwise the transformations won't be correct. For example: if we add or subtract the w values during two vectors addition we might have unexpected projections when the new w value is > 1 or divisions by 0 (when the new w is 0) because opengl divides the x,y,z values by w.

Solution:
- Changed the constructors to initialize w to 1 and not to 0 by default.
- Fixed the vector operations to use the x, y, z coordinates only.
- Fixed the existing constructors in plugins to initialize w to 1 and not to 0.