- Added ant target updatePackageXmlManaged for generating a package xml
  for the managed package which may have extra attributes.
- Pass installClass and uninstallClass scripts in package xml generation
  for managed package deployments to the packaging org
- Modify deployCIPackageOrg to call updatePackageXmlManaged before
  deployment to dynamically build the managed version of the package.xml
- Removed runAllTests from deployManagedUAT as it can be called after
  deployment via the runAllTests target
Add support for postInstallClass and uninstallClass elements
Move hardcoded values to properties file to make build more generic and
easier to perform common edits
Merge pull request #552 from SalesforceFoundation/feature/503-build-includes-install-scripts

Feature/503 build includes install scripts