[Launcher] Modify scenario build to account for changes to launcher

Background: As Derby is used by default by Launcher (nasa/mct#143), "derby.properties" simply became "persistence.properties", whereas the old "persistence.properties" became "mysql.properties"

The scenario assembly does some setup of database parameters (configured via maven arguments) by modifying persistence.properties, but expects mysql settings (as this distribution runs on a mysql database). This is managed by:
* Performing the "replace" step used for DB configuration on mysql.properties (instead of persistence.properties)
* Moving mysql.properties to persistence.properties in the subsequent assembly stage (omitting the unused derby configuration)

Also fixed is a source/target incongruity in quickstart-assembly, related to Java 7 compatibility nasa/mct#142