Tabs shortcuts

I'm trying to make usability easier and faster by adding some shortcuts (common in software with tabs) as:

Add shortcut to add new tab (Ctrl + T);
Add shortcut to close tab (Ctrl + W);
Add Double Click to Rename Tab;
Update Credits to 2014 year;

I am also working on adding buttons to close tabs, like a browser.

I changed the fields where numbers are entered for the NumericUpDown type, it facilitates the user to increase and decrease the values ​​and forcing the user to enter only numbers in these fields.