cleanup of a few tested/resolved todos

src/epd1in54/mod.rs

@@ -223,7 +223,6 @@ where
         // clear the ram with the background color
         let color = self.background_color.get_byte_value();
 
-        //TODO: this is using a big buffer atm, is it better to just loop over sending a single byte?
         self.interface.cmd(spi, Command::WRITE_RAM)?;
         self.interface.data_x_times(spi, color, WIDTH / 8 * HEIGHT)
     }

src/epd2in9/mod.rs

@@ -222,7 +222,6 @@ where
         // clear the ram with the background color
         let color = self.background_color.get_byte_value();
         
-        //TODO: this is using a big buffer atm, is it better to just loop over sending a single byte?
         self.interface.cmd(spi, Command::WRITE_RAM)?;
         self.interface.data_x_times(spi, color, WIDTH / 8 * HEIGHT)
     }

src/epd4in2/mod.rs

@@ -55,7 +55,7 @@ use interface::DisplayInterface;
 use traits::{InternalWiAdditions, RefreshLUT, WaveshareDisplay};
 
 //The Lookup Tables for the Display
-mod constants; //TODO: Limit to crate::drawing
+mod constants;
 pub use self::constants::*;
 
 use color::Color;
@@ -278,9 +278,6 @@ where
         self.interface
             .data_x_times(spi, color_value, WIDTH / 8 * HEIGHT)?;
 
-        //TODO: Removal of delay. TEST!
-        //self.delay_ms(2);
-
         self.interface
             .cmd(spi, Command::DATA_START_TRANSMISSION_2)?;
         self.interface