Replaced ClutterFixed constants in color_{darken,lighten} with float
Replaced ClutterFixed constants in color_{darken,lighten} with float

Bug 1463 - clutter_color_lighten(darken) unexpected because of
           ClutterFixed=>float

These two functions contained ClutterFixed constants represented as
integers which are no longer valid since the cogl-float branch
merge. They are now converted to ClutterFixed from float constants
using CLUTTER_FLOAT_TO_FIXED (which is now a no-op).

Thanks to Zhang Wei for reporting.

Distrotech/clutter,rkudiyarov/clutter_osx,djdeath/clutter-multithreaded,rkudiyarov/clutter_osx,collects/clutter,spatulasnout/clutter,tardyp/clutter,djdeath/clutter,djdeath/clutter-multithreaded,rkudiyarov/clutter_osx,djdeath/clutter,nobled/clutter,Distrotech/clutter,djdeath/clutter,spatulasnout/clutter,jigpu/clutter,Distrotech/clutter,GNOME/clutter,collects/clutter,ebassi/clutter,spatulasnout/clutter,Distrotech/clutter,heysion/clutter-clone,collects/clutter,djdeath/clutter-android,ebassi/clutter,collects/clutter,jigpu/clutter,kerrickstaley/clutter-vala,Distrotech/clutter,kerrickstaley/clutter-vala,nobled/clutter,heysion/clutter-clone,jigpu/clutter,ebassi/clutter,djdeath/clutter-android,jigpu/clutter,spatulasnout/clutter,collects/clutter,GNOME/clutter,kerrickstaley/clutter-vala,GNOME/clutter,djdeath/clutter,jigpu/clutter,Distrotech/clutter,djdeath/clutter-android,spatulasnout/clutter,GNOME/clutter,jigpu/clutter,tardyp/clutter,ebassi/clutter,heysion/clutter-clone,djdeath/clutter,kerrickstaley/clutter-vala,djdeath/clutter-android,dlespiau/clutter,GNOME/clutter,djdeath/clutter-multithreaded,nobled/clutter,rkudiyarov/clutter_osx,heysion/clutter-clone,ebassi/clutter,dlespiau/clutter,djdeath/clutter,djdeath/clutter-android,tardyp/clutter,heysion/clutter-clone,djdeath/clutter-multithreaded,dlespiau/clutter