#60 Check for .xar on package creation

[D. Black]

Ensure that when creating a package in the Package Assembly Tool that the correct (.xar) extension is either on or added to the file name. If a user renames the package and does not put the .xar extension on, it will save the package without the .xar rendering it deployable but can then not be located by the Engine on app server restart. See XAware.org forum post http://www.xaware.org/forums/usage-and-operation/xaware-app-cannot-survive-app-server-reboot/view-3.html#4896