Even if they are in attic and not actually in use, drop a number of
modules (and old tests) that it does not make sense to keep carry
further:

- FindAlsa.cmake, config-alsa.h.cmake:
cmake has been providing a better FindALSA for long time

- FindEigen.cmake, FindEigen2.cmake & test:
Eigen v1 & v2 are deprecated and unmaintained for years

- FindGStreamer.cmake:
gstreamer-0.10 is long dead upstream

- FindKdcraw.cmake, FindKDE4Workspace.cmake, FindKdeMultimedia.cmake,
  FindKDevPlatform.cmake, FindKexiv2.cmake, FindKipi.cmake,
  FindLibAttica.cmake, FindLibKonq.cmake:
modules for KDE 4 libraries -- they are provided already by kdelibs 4.x,
and the frameworks versions of those libraries provide cmake config
files already

- FindKNepomuk.cmake, FindKonto.cmake, FindNepomuk.cmake,
  NepomukAddOntologyClasses.cmake, NepomukMacros.cmake:
Nepomuk stuff, which is long dead

- FindKopete.cmake:
the Frameworks version of Kopete is not released yet, so it'd rather
provide own cmake config files

- FindKorundum.cmake:
Korudum is dead upstream, and so is Ruby 1.8

- FindLCMS.cmake & test:
LCMS 1 is dead for many years already

- FindMusicBrainz.cmake:
libmusicbrainz v2 is long dead, and the web service API it uses was
dismantled years ago

- FindOpenEXR.cmake & test:
ECM already provides an improved and polished version of this module

- FindPolkitQt.cmake:
polkit-qt is long dead, replaced by polkit-qt-1

- FindPopplerQt4.cmake:
ECM 5.19+ already provides a better FindPoppler module

- FindSharedDesktopOntologies.cmake:
dead upstream, but also used to provide cmake config files already

- tests for Blitz, Flex, LibXslt:
their modules are not even in attic