libical: dropping C++ bindings

[Debarshi Ray]

I am planning to disable the C++ bindings from libical-0.41 onwards.
The last time I had asked upstream, which was couple of months back,
they said that they knew of no user of the bindings and are not very
keen to maintain them. Moreover the Makefiles are broken causing a
number of undefined symbols to be present in the C++ bindings' shared
libraries. Patching the Makefile.ins with every release is not very
enjoyable, especially since upstream is not interested.

If someone is using or plans to use libical's C++ bindings then please
let me know.

Thanks,
Debarshi