[Nc-GUI][ref #137] Improved event dispatch on widgets.
Added management of the scroll via the mouse on the ScrollArea/ScrollBar.
[Nc-Core] Added operator + on the Unicode class UTF32.
[Nc-GUI][ref #137] Improved management of the LineEdit.
 - Add management of arrow keys to move along the text
 - Possibility to move the cursor and insert text in the middle.
 - Possibility to write text longer than the box and display the text where the cursor is properly, just like any normal LineEdit.
Merge branch 'dev' of github.com:PoncinMatthieu/3dNovac into dev