Add state class
Adjust implementation to current State class
Allow clearing state
Separate testing of Q construction vs execution
Adjust test case to the new State class
Make state remember last inserted id
 Task graph should only store ID
Store filter by value in FilterTask
Implement updating task in graph
Implement and test CRUD
Merge pull request #140 from evansb/implement-state

Add state class
When we are accumulating characters for a description, include spaces. Fixes #144.
No need for a console window.
Add some space for readability.
Use forward slashes in #includes

Conflicts:
	You-QueryEngine-Tests/filter_tests.cpp
Add more files to the PCH for faster compiles.
 - Use references where possible
 - Use unique_ptr so that we don't leak memory
 - Use std::transform to map from std::wstring to QString.
Normalise TODO syntax.
Move the application icon and store it in the .qrc file.

Resolves #141.
Place the query result processor exactly where it is used. It is local, so no need for global definitions.