comment out mains

core/java/src/net/i2p/util/ResettableGZIPInputStream.java

core/java/src/net/i2p/util/ResettableGZIPOutputStream.java

core/java/src/net/i2p/util/ReusableGZIPInputStream.java

core/java/src/net/i2p/util/ReusableGZIPOutputStream.java