Bug 37197 Basepath for relative pathes in JAR-exporter
The basepath for the JAR-exporter is the eclipse-install-directory. I prefer it to be the root of the project (the description is saved in), so that relative pathes end inside the project. Now: <jardesc> <jar path="workspace/projectdir/jar.jar"/> Desired: <jardesc> <jar path="jar.jar"/> Reason: To make the jardesc-files portable for shared projects
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/jarpackager/JarPackageData.java
* 
	 * @param sealJar <code>true</code> if the JAR must be selead
	 * @see #isManifestGenerated()
	 */
	public void setSealJar(boolean sealJar) {
		fSealJar= sealJar;
	}
	/**
	 * Set the packages which should be sealed.
	 * The following entry will be added to the manifest file for each package:
	 * Name: <name of the package>
	 * Sealed: true
	 * <p>
	 * This should only be used if the JAR itself is not sealed.
	 * </p>
	 * 
	 * @param packagesToSeal an array of <code>IPackageFragment</code> to seal
	 */
	public void setPackagesToSeal(IPackageFragment[] packagesToSeal) {
		fPackagesToSeal= packagesToSeal;
	}
	/**
	 * Gets the packages which should be sealed.
	 * The following entry will be added to the manifest file for each package:
	 * Name: <name of the package>
	 * Sealed: true
	 * <p>
	 * This should only be used if the JAR itself is not sealed.
	 * </p>
	 *