[xilinxc]: Added four different ucf files for each kind of clock: internal, weblab, swi9, but3. Inputs outputs are renamed to be shorter.
[xilinxc]: Four different clocks are now supported: weblab, internal, switch and button. The compiler will choose the UCF for the appropriate one depending on whether a specific directive can be found or not.
Merge branch 'master' of https://github.com/weblabdeusto/weblabdeusto