Feature request: extra painting tool suggestions

[slippifishi]

• Pixel palette replace tool (For the purposes of this example, a palette is made up of 16 colours, held in 4 "indexes" of 4 colours) Given I have a pixel which is currently using colour a from palette X index 0, let me replace ALL pixels in the scene using colour a from palette X index 0 with colour b from palette X index 2. (This is not "use colour mask replacement to achieve it" this is "i want to replace all instances of the use of one colour in the scene with a different colour, in a single click, instead of clicking individual pixels"). I can provide a better example if needed.

• An adjustable size pencil/brush tool For example, instead of painting one pixel at a time, paint a square of 2x2, or 3x3 or 4x4 etc...

• Dashed-line tool Similar to the existing line tool, but instead of painting every pixel, paint every other pixel

[lucky01]

added toolSize spinner to layout with the following functions

• replace all pixels in the scene using selected colour if toolSize > 1
• set brushSize
• select dash size