packages: Move remove(), pre_install(), post_install() to debfetcher

packages/signal.debfetcher

@@ -7,21 +7,6 @@ PACKAGE="signal-desktop"
 TS=$(date +%s)
 THIS_BASEDIR="/opt/Signal"
 
-remove()
-{
-    rm -rf -- "${DEBFETCHER_INSTALL_DESTDIR}/${THIS_BASEDIR}"
-}
-
-pre_install()
-{
-
-    CURRENT_DIR="${DEBFETCHER_INSTALL_DESTDIR}${THIS_BASEDIR}"
-
-    if [ -d "${CURRENT_DIR}" ] ; then
-      mv -- "${DEBFETCHER_INSTALL_DESTDIR}${THIS_BASEDIR}" "${DEBFETCHER_INSTALL_DESTDIR}${THIS_BASEDIR}_${TS}"
-    fi
-}
-
 install()
 {
     #Inspired by Gentoo's ebuild
@@ -34,11 +19,3 @@ install()
     
     ln -sf ${DEBFETCHER_INSTALL_DESTDIR}/opt/Signal/signal-desktop "${DEBFETCHER_BIN_SYMLINK_DIR}" 
 }
-
-
-post_install()
-{
-    if [ ${KEEP_OLD} -eq 0 ] ; then
-        rm -rf -- "${DEBFETCHER_INSTALL_DESTDIR}${THIS_BASEDIR}_${TS}"
-    fi
-}