[Bf-docboard] Part IV Textures: Major changes, please revise

[Ivailo Stoimenov]

Some small corrections just spoted:

* Texture_Channels
	- Clear: deletes the Textur. -> Clear: deletes the Texture.
	- Num-Button: shows the number of Objekts -> Num-Button: shows the number  
of Objects

* MapTo
	-  The Alpha value ist normally 1, set DVar ->  The Alpha value is  
normally 1, set DVar

Nice job Tobias :)