Initial commit
Initial work on a D Presto Client

Can successfully query results. Thus far mostly been fighting the JSON
library to get the data into a type-checked and user-friendly state.
Everything written is in a highly volitile state and may be refactored.
Refactor for review.
dataAs is no longer @property
Explicitly mentioning return type of jsonValueAs instead of using auto
Cleaning up imports
Converted dataAs function into a range-based interface
Now allows/requires the range to retrieve a named set of fields
Cleanup: low hanging fruit
Refactored into multiple files.
First version of StatementClient
Cleanup
Sends DELETE to Presto when StatementClient falls out of scope.
Prevent misuse of StatementClient after it has been manually closed
Added unit tests to all files.
QueryResults is now immutable-friendly

This enables ease-of-use for concurrent processing.
Switched Makefile rules to pattern matching, made other suggested fixes
Prod and unittest executables
Rearranged a couple functions to top-down ordering
Renamed resultSet to resultBatch