Update dependencies. Publish 0.45.0.

[mitchmindtree]

Bump the minor version in order to publish several breaking changes:

• PistonWindow fork #850 removing the old piston_window feature in favour of a conrod-specific piston window
• Complete glium.rs backend and update glutin_glium.rs example accordingly. #852 completes the glium backend and fixes the glutin event conversions
• Remove event::Raw in favour of using event::Input #855 removes the unnecessary event::Raw type in favour of the more minimal event::Input type
• Enhanced textedit #849 added some slight features to TextEdit widget