DRILL-466: fixing when submit_plan fails does not terminate the program
DRILL-332: Support for decimal data type
DRILL-323: Handle multiple inputs to math operators correctly.
DRILL-553: simple query fails sometimes

Initialize lastSet variable in NullableVarLength vectors to -1. Also reset when reallocating.
DRILL-442: Implement text format plugin

rename storage-engines.json storage-plugins.json
allow reading a particular value in a repeated vector
fix test caused by change that allows selecting element of repeated record
set def recordCount for explain query
fix bug loading repeated vectors
storage plugin/format plugin changes. store storage plugin configuration in distributed cache.
add repeated vector allocators
add support for for reading compressed files.
DRILL-468 Support for FileSystem partitions
DRILL-452: Conversion functions for external data types