Bug 82804 Jar creation should use less memory
I noticed that the JarWriter will read the entire file it plans to store into memory. An optimization would be to stream the file directly into the JarOutputStream. The only catch is with STORED items which need the CRC32 computed. A penalty could be taken in that case to compute the CRC in a loop and then stream the file.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/jarpackager/JarPackageData.java
* @param manifestVersion the string which contains the manifest version
	 */
	public void setManifestVersion(String manifestVersion) {
		fManifestVersion= manifestVersion;
	}
	
	/**
	 * Answers whether a manifest must be included in the JAR.
	 * 
	 * @return <code>true</code> if a manifest has to be included
	 */
	public boolean usesManifest() {
		return fUsesManifest;
	}
	
	/**
	 * Sets whether a manifest must be included in the JAR.
	 * 
	 * @param state the new state
	 */
	public void setUsesManifest(boolean state) {
		fUsesManifest= state;
	}
	
	/**
	 * Gets the manifest provider for this JAR package.
	 * 
	 * @return the IManifestProvider
	 */
	public IManifestProvider getManifestProvider() {