Fix #30: Cleanup unnecessary files

First, delete all the old files inside folders "view" and "controller".
These are unnecessary files, created from the first iteration.
Fix #30: Move all required files to MVC folders

Change the existing structure of view files, model files and controller
files being in the same place. Instead distribute them to specific
folders - QML files to "view", JS files to "controller" and DB files to
"model"

Add "view", "model" and "controller" folders to
HistoryProjectQt.qmlproject main file.

Put Line-related files in respective MVC folders.