AnyKernel2: custom user script support, fixes

- fix copy of any subdirectories under modules/
- adjust display of modules installation text to match the others
- add support for custom user scripts (at /data/custom_boot_image_patch.sh - same as latest SuperSU zips) to automatically execute before reflashing the rebuilt boot image for bump, loki etc. modifications

anykernel.sh

@@ -89,6 +89,12 @@ write_boot() {
   elif [ `wc -c < /tmp/anykernel/boot-new.img` -gt `wc -c < /tmp/anykernel/boot.img` ]; then
     ui_print " "; ui_print "New image larger than boot partition. Aborting..."; exit 1;
   fi;
+  if [ -f "/data/custom_boot_image_patch.sh" ]; then
+    sh /data/custom_boot_image_patch.sh /tmp/anykernel/boot-new.img;
+    if [ $? != 0 ]; then
+      ui_print " "; ui_print "User script execution failed. Aborting..."; exit 1;
+    fi;
+  fi;
   dd if=/tmp/anykernel/boot-new.img of=$block;
 }