public static void unzip(File zippedFile, File destDir, String charsetName) {
		try {
			unzip(new FileInputStream(zippedFile), destDir, charsetName);
		} catch (FileNotFoundException e) {
			throw processException(e);
		}
	}
Unzip the given zipped file into destination directory with the given
character set.

@param zippedFile  zipped file
@param destDir     destination directory
@param charsetName character set name
ngrinder-core/src/main/java/org/ngrinder/common/util/CompressionUtils.java