More progress for the pidgin++ package.

* Disable the Sametime and SILC protocols.
  Pidgin++ has been updated to support this and also use the TCL library from
  MSYS2. Now the remaining binary downloads are pidgin-inst-deps and WinSparkle.

* Install EasyOptions.

* Add pidgin as a conflicting package.

* Fix missing checkout for the Bazaar branch.

* Update makedepends and other small changes.