Fixed bad assembly of dropin libs in the stratosphere-bin shell scripts.

The jarfile loop for the dropins folder doesn't work because of bad folder name (`dropins`, should be `dropin`).

The push request also fixes a bad bash variable name in `pact-webfrontend.sh`.

In addition, I suggest to add the folder itself to the java classpath for extra, non JAR file resources that need to be included in the classpath (e.g. license files for vendor libraries).