kde5.eclass: Inherit ecm.eclass and drop moved functions/vars

kde5.eclass: Inherit ecm.eclass and drop moved functions/vars

Functions moved to ecm:
- All phase functions so far exported by kde5

Variables moved to ecm:
- ECM_KDEINSTALLDIRS
- KDE_DEBUG (-> ECM_DEBUG)
- KDE_DESIGNERPLUGIN (-> split into ECM_DESIGNERPLUGIN, KDE_DESIGNERPLUGIN)
- KDE_EXAMPLES (-> ECM_EXAMPLES)
- KDE_HANDBOOK (-> ECM_HANDBOOK)
- KDE_DOC_DIR (-> ECM_HANDBOOK_DIR)
- KDE_PO_DIRS (-> ECM_PO_DIRS)
- KDE_QTHELP (-> ECM_QTHELP)
- KDE_TEST (-> ECM_TEST)

Variables deprecated:
- KDE_AUTODEPS (re-use as a switch to inherit ecm or cmake-utils)

Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>