Revert "TEZ-695. Create Abstract class for Input/Processor/Output (Mohammad Kamrul Islam via bikas)"

This reverts commit 6e07f0388b4a99a7d921ea697fb0c6cad2cea674.
TEZ-695. Create Abstract class for Input/Processor/Output (Mohammad Kamrul Islam via bikas)
TEZ-695. TEZ-988. Enable KeepAlive in Tez Fetcher (Rajesh Balamohan via bikas)