AppImage: Bundle more binaries to increase compatibility

This slightly increases the AppImage size but allows us to be more
compatible with older distributions.

-----

taken from Electron-Cash/Electron-Cash@96644acd6f

contrib/build-linux/appimage/Dockerfile

@@ -21,7 +21,7 @@ RUN apt-get update -q && \
         libudev-dev=204-5ubuntu20.31 \
         gettext=0.18.3.1-1ubuntu3.1 \
         libzbar0=0.10+doc-9build1  \
-        faketime=0.9.5-2 \
+        libdbus-1-3=1.6.18-0ubuntu4.5 \
         && \
     rm -rf /var/lib/apt/lists/* && \
     apt-get autoremove -y && \

contrib/build-linux/appimage/build.sh

@@ -157,12 +157,8 @@ info "finalizing AppDir."
 
     cd "$APPDIR"
     # copy system dependencies
-    # note: temporarily move PyQt5 out of the way so
-    # we don't try to bundle its system dependencies.
-    mv "$APPDIR/usr/lib/python3.6/site-packages/PyQt5" "$BUILDDIR"
     copy_deps; copy_deps; copy_deps
     move_lib
-    mv "$BUILDDIR/PyQt5" "$APPDIR/usr/lib/python3.6/site-packages"
 
     # apply global appimage blacklist to exclude stuff
     # move usr/include out of the way to preserve usr/include/python3.6m.
@@ -171,10 +167,12 @@ info "finalizing AppDir."
     mv usr/include.tmp usr/include
 ) || fail "Could not finalize AppDir"
 
-# copy libusb here because it is on the AppImage excludelist and it can cause problems if we use system libusb
-info "Copying libusb"
-cp -f /usr/lib/x86_64-linux-gnu/libusb-1.0.so "$APPDIR/usr/lib/libusb-1.0.so" || fail "Could not copy libusb"
-
+# We copy some libraries here that are on the AppImage excludelist
+info "Copying additional libraries"
+(
+    # On some systems it can cause problems to use the system libusb
+    cp -f /usr/lib/x86_64-linux-gnu/libusb-1.0.so "$APPDIR/usr/lib/libusb-1.0.so" || fail "Could not copy libusb"
+)
 
 info "stripping binaries from debug symbols."
 # "-R .note.gnu.build-id" also strips the build id