#50 Query input improvements

This adds the following features to the query mode:

1. The ability to edit queries with the arrow keys
2. Command history, with the last 1000 entires stored in a history file for persistence
3. Completion of partially typed commands and suggestions by using the TAB-key
4. A help command, listing available commands and providing examples and additional information by typing "help [KEYWORD];"
5. A labels command, which lists all attacks list in the label file (if any)

Disclaimer: Some of the queries listed in the help require the fixes contained in my other pull requests to function.

This pull request resolves issues #6, #4 and part of #15.