VXQUERY-131: Support for reading HDFS XML files.
1. User can choose between local and HDFS file systems for data input
2. New collection-with-tag function that reads from HDFS by blocks
3. Collection and Document can both read HDFS
4. Custom InputFormatClass for XML in HDFS
5. Parsing of data from HDFS as whole files
6. Unit tests for HDFS
7. MiniDFS cluster for unit tests
8. Documentation
9. Allow user to pass HDFS config folder as a param to queries
Author: Efi Kaltirimidou github: efikalti
45 files changed
