[cooja] plugins/analyzers: Indention and whitespace cleanups
[cooja] plugins/analyzers: Added @Override annotations
[cooja] plugins/analyzers: Replace StringBuffer with lightweight StringBuilder

StringBuffer is a thread-safe version of StringBuilder that introduces
unnecessary overhead.

Additional replaced concatenations with .append()
[cooja] plugins/analyzers/IEEE802154Analyzer: More verbose printout including FCF information
[cooja] plugins/analyzers/IPHCPacketAnalyzer: fixed ttl encoding,
addded hlim decoding
[cooja] plugins/analyzers/PacketAnalyzer: Fixed integer assembly from bytes in getInt() method
[cooja] plugins/analyzers/IPHCPacketAnalyzer: Full port decompression for UDP header compression
[cooja] plugins/analyzers/IPHCPacketAnalyzer: Hack for basic Hop-by-hop extension header handling
[cooja] plugins/analyzers/IPHCPacketAnalyzer: More verbose output of IPHC options
[cooja] plugins/analyzers/ICMPv6Analyzer: DTSN field is unsigned
[cooja] plugins/analyzers/ICMPv6Analyzer: Short names for ICMP types in brief output and more reader-friendly long names
[cooja] plugins/analyzers: printout of UDP ports and clearer layer separation
Merge pull request #763 from ejoerns/pull-req/cooja-analyzers

[Cooja] Fixes and enhancements for 6lowpan analyzers