Pretty print AvroFileViewer
Added HDFSViewer src and libs to .classpath
Removed unused imports to fix Eclipse warnings
Merge pull request #86 from erwa/avro-pretty-print

HDFS Viewer should pretty-print the Avro schema
Clean up HdfsBrowserServlet and make it possible to check for file access issues when checking viewer capabilities.
Fix NullPointerException in SequenceFileReader caused by AzkabanSequenceFileReader suppressing IOException in AzkabanSequenceReader.Reader's constructor.
Surround body of handleAjaxAction in a try/finally. Fix no_fs in HDFS file page.
Indentation changes.
Merge pull request #87 from davidzchen/hdfs-perm-error

HDFS Viewer displays "error: null" when permission is denied
merging from upstream