[squash] split common data

instead of building the packaged binaries with the `bindata` tag, this
introduces a new forgejo-common package which contains common assets and
architecture independent files.

This is the first of a handful of PRs that will ultimately enable
building packages for multiple architectures.

deb/debian/forgejo.preinst

@@ -1,34 +0,0 @@
-#!/usr/bin/env bash
-case "$1" in
-  install|upgrade)
-  [ -f "/etc/default/forgejo" ] && . /etc/default/forgejo
-  [ -z "$FORGEJO_HOME" ] && FORGEJO_HOME=/var/lib/forgejo
-  [ -z "$FORGEJO_USER" ] && FORGEJO_USER=forgejo
-  [ -z "$FORGEJO_NAME" ] && FORGEJO_NAME="Forgejo (Beyond coding. We forge.)"
-  [ -z "$FORGEJO_GROUP" ] && FORGEJO_GROUP=forgejo
-  if ! getent group | grep -q "^$FORGEJO_GROUP:" ; then
-    echo -n "Adding group $FORGEJO_GROUP.."
-    addgroup --quiet --system $FORGEJO_GROUP 2>/dev/null ||true
-    echo "..done"
-  fi
-  test -d $FORGEJO_HOME || mkdir $FORGEJO_HOME
-  if ! getent passwd | grep -q "^$FORGEJO_USER:"; then
-    echo -n "Adding system user $FORGEJO_USER.."
-    adduser --quiet \
-            --system \
-            --ingroup $FORGEJO_GROUP \
-            --no-create-home \
-            --disabled-password \
-            $FORGEJO_USER 2>/dev/null || true
-    echo "..done"
-  fi
-  usermod -c "$FORGEJO_NAME" \
-          -d $FORGEJO_HOME   \
-          -g $FORGEJO_GROUP  \
-	  -s "/bin/bash"     \
-             $FORGEJO_USER
-  if ! dpkg-statoverride --list $FORGEJO_HOME >/dev/null ; then
-    chown -R $FORGEJO_USER:$FORGEJO_GROUP $FORGEJO_HOME
-    chmod u=rwx,g=rx,o= $FORGEJO_HOME
-  fi
-esac