Small fixes for cross platform support

Some small bugs have been fixed for Windows.

Updates:

• Bigglesworth now uses Droid font (still under evaluation), which would allow better consistency across platforms.
• Personal library is now saved in the "Data Location" user folder, which is:
  • for Linux: $HOME/.local/share/data/jidesk/Bigglesworth/
  • for Windows: %APPDATA%\jidesk\Bigglesworth\
• Better quality Windows icon.

Some issues still remain:

• Combobox drop down in the editor window now appear, but clicking on the arrow buttons or the scroll bar make the listview disappear again. If you have a wheelmouse, use that.
• HiDPI screens are not supported.

Notes:
The linked source code below correctly refers to the current release.