#52 Support both Itk and itk package names for itk-4.0.0

[Alan W. Irwin]

Both

package require itcl

and

package require Itcl

work for itcl-4.0.0. This small patch gives the same "itk" and Itk capability to itk-4.0.0, i.e., adds the "Itk" package name to the existing "itk" package name. Some packages that use "package require Itk" inside will not work without the current patch.

[Alan W. Irwin]

The comparisons in the title of this patch and in the text should be "Itk" versus "itk" and "Itcl" versus "itcl". (For some strange reason sourceforge lower-cased the leading "I" characters in my initial submit of the title and explanatory text for this patch.)