Removed lazy param and isConstant from operations
Fix camera casts

it is natural to write viewport resolutions in pixels; however, viewport
calculations are done in float coordinates. This fixes, for example,
the CoolDemo
Merge pull request #643 from manuel-freire/fix-camera-casts

Fix camera casts
Simplified methods to create icons buttons
Refactor in buttons creation
Fix bug in IconButton
Bug fix in ReorderSelection
Bug fixes in camera and debugview
Merge pull request #642 from anserran/opsimpl

Removed lazy param and isConstant from operations
Merge pull request #647 from anserran/sbf

Bug fixes related to enable state in icon buttons
Merge pull request #648 from anserran/camerasfix

Bug fixes in camera and debugview