Implement API for batch addition and deletion
Implement subtask
Remove dynamic_cast
Change to move constructor
lint fix
Merge pull request #294 from evansb/subtask-api

Subtask API without Undo support
Use the expect operator where possible since it is more efficient.

Conflicts:
	You-NLP/query_parser.cpp
Use more expects when using explicit commands.

Conflicts:
	You-NLP/query_parser.cpp
Test for #287 by demonstrating that the show command can be used without a space delimiter.
Merge pull request #289 from angathorion/highlight-dependencies

Highlight dependencies
Merge pull request #293 from lowjoel/use-expect-where-possible

Use the expect operator where possible since it is more efficient.
Refactoring.