Improved julia implementation of Computus

[Vexatos]

Replaced division and flooring with actual floor division. Also prettified formatting and print statements.

[Vexatos]

It may be considered whether to use % and ÷ instead of mod and fld. In this case, they would be functionally identical, but use infix notation instead, which might or might not be easier to read.

[jiegillet]

Nice. The inconsistent spacing was bugging me :)
I would keep fld and mod over their symbol version, more readable.

[leios]

Yup, thanks for cleaning this up!