[core] Add python-snappy library
[core] make snappy a first class citizen
[core] add parquet-python library
[core] update parquet-python to use file objects
[filebrowser] read parquet in filebrowser

Rudimentary test for verifying output is not binary
[beeswax] Close HiveServer2 and Impala session command

  e.g. Close all HiveServer2 sessions created by Hue
  build/env/bin/hue close_sessions 0 hive

  e.g. Close all HiveServer2 and Impala created by Hue at least one week ago
  build/env/bin/hue close_sessions 7 all
[desktop] A user can share a document to a group he does not belong too
[filebrowser] Snappy decompression error should throw PopupException