Application: gvSIG desktop

 * <p>

 * This service is used to create an installer for a gvSIG plugin. It 

 * supports just one plugin for every installer. It contains a method to

 * set the plugin path and some methods to set the installer information.

 * </p>

 * 

 * <p>

 * It has also methods to load the current installation information (if exists)

 * and methods to create the installer file from an {@link OutputStream}.

 * </p>

 * 

 * <p>

 * An installer is just a compressed zip file that has a compressed zip file

 * for every plugin to install. In this first version it only has a plugin, but

 * in a future it is possible to create installers with more that one plugin.

 * The structure of an installation file is:

 * </p>

 * <pre>

 * - installer.zip

 * 		- org.gvsig.myplugin-[version]-[build].zip

 * 			- org.gvsig.myplugin

 * 			  	- install.info

 *  			- install.xml

 *  			- files

 *  				- org.gvsig.otherplugin

 *  					- file1

 *  					- file2

 * </pre>

 * <p>

 * installer.zip is the installer file name that has a zip file that 

 * contains the plugin to install (org.gvsig.myplugin-[version]-[build].zip).

 * This second file has a root directory with the plugin content and with

 * some extra files with the installer information. These files are:

 * </p>

 *  

 * <lu>

 * <li><b>install.info</b>: file that contains the installer information</li>

 * <li><b>install.xml</b>: ant file that is executed in the execution of the installer

 * to do some extra actions in the installation process. One of these actions

 * is copy all the files located in the files directory</li>

 * <li><b>files directory</b>: it contains some files of other extensions that have

 * to be copied using the ant script.</li> 

 * </lu>

 *  

 * <p>

 * The usage of the ant script to copy files from other plugins is not recommended 

 * because it is possible that different installers overrides the same file. The 

 * suggestion it that one plugin has to have all the files that it needs to work

 * inside the plugin and it never has to override some external files. 

 * </p>

	/**

	 * It returns an instance of an {@link InstallerInfo} class, that is a 

	 * class that contains all the installer information (plugin name, plugin

	 * version...).

	 * @return

	 * The installer information.

	 */

	/**

	 * It sets the directory where the plugin is located, that it has to

	 * be a valid gvSIG plugin directory. 	

	 * @param pluginDirectory

	 * The directory where the gvSIG plugin is located.

	 * @throws InstallerCreationServiceException

	 * This exception is thrown when the directory doesn't exist or the directory is

	 * not a valid gvSIG plugin directory.

	 */

	/**

	 * This method reads the install.info file and loads the installation information

	 * into the current installer creation process. It also reads the information to 

	 * copy some external files and add them to the current installer creation execution.

	 * @throws InstallerCreationServiceException

	 * This exception is thrown when the directory is not valid gvSIG plugin directory.

	 */

	/**

	 * It creates the installer file and copy it in the stream received like

	 * an argument.

	 * @param installerStream

	 * The stream where the the installer is created

	 * @throws InstallerCreationServiceException

	 * It is thrown when there is an exception creating the installer.

	 */