Add binary file encoding.

Fix terminator not being added

Re-add image size specifying, with better error handling.

Start separating image creating functions into it's own file.

Also moved search_for_minimum_satisfier into utils.rs.

Add error propagation and minimum image size finder.

Finds the minimum image size by starting at the
minimum possible image size constrained by
the number of instructions and then checks if
trying to convert the instructions results in an
error.
This can happen when the terminator doesn't have
enough room or when the blocks outnumber the
available space on the spiral.

Need to separate search_for_minimum_satisfier into
a util.rs.

Clean up old comments and terminator placement logic.

Refactor terminator placement.

Add checking if terminator can be placed safely.

Add minimum image size finder.

Still buggy due to pushes on corners adding more
blocks than expected. Should fix

Refactor text encoding into instructions in Encoder trait.

Add bfs based instruction generation

Clean up loose png's

Add basic README and LICENSE

Increase MINOR version

Add output file option to args

Clean up main.rs splitting it up into instructions.rs
Add Lusíadas

Improve img_size estimation

Add first attempt to predict the size of the instruction spiral.
Next step should be to walk through the instructions and count how many
blocks each will need to enhance the predictability of the spiral size.

Add color filling

Add spiral struct and iterator for image output