When an user first opened an ePUB, then a PDF, it didn't work. This was
due to an issue with the two tmpfs at '/kobo/inkbox' and '/kobo/run'.
This commit fixes that issue.

On this device, the Quit button makes the UI go beyond the limits of the screen when the menu bar is shown. Thus, the user will have to resort on the default Quit button found in MainWindow.

Inter is still there in a lot of areas and blends quite well with this new font.

Otherwise, we get some memory issues ...

Finally applying @NiLuJe's suggestion!

See commit https://github.com/Kobo-InkBox/inkbox/commit/
6155e934 for details.

When an user would click another button-tab (e.g. Settings or Apps)
after launching libraryWidget, InkBox would reset the window entirely
and get back to the Home widget. The user would then have had to re-
click on the button-tab he wanted to pick to get the appropriate
content.

This commit fixes this issue by requiring a resetFullWindowException
boolean variable to be set to false (meaning that the user didn't click
on any button-tab before leaving libraryWidget) for the
resetWindow(true) function to occur as described in resetFullWindow(),
when libraryWidget is destroyed.

Update README.md