Merge pull request #48 from bvssvni/master

Going back to PistonDevelopers sdl2_game_window
Merge pull request #60 from bvssvni/master

Replaced `Color` with `Color([f32, ..4])`
Add number_dialer example
Added number_dialer module
Added NumberDialer widget
Started work on number_dialer module
changed  to
Merge remote-tracking branch 'upstream/master'

Merging color.rs changes
Implemented macro for widget module boilerplate, started on number_dialer widget (still WIP)
Merge pull request #63 from mitchmindtree/master

Implemented macro for widget module boilerplate and started on number_dialer module (still WIP)
Changed widget_boilerplate_fns to widget_fns, removed now unnecessary  macro
Merge pull request #64 from mitchmindtree/master

Changed `widget_boilerplate_fns` to `widget_fns`, removed unnecessary  `widget_state` macro