Support for figlet control files

[ColOfAbRiX]

Description

As a user of the figlet4s library I would like to be able to use figlet control files FLC

Implementation

I have not tested much this feature in the original figlet but its definition can be found in the main standard: http://www.jave.de/figlet/figfont.html#controlfiles

Figlet4s should implement the behaviour described above and where there are doubts on the implementation it should behave as the original figlet does.

Similar features in the wild

See the figlet man page: https://linux.die.net/man/6/figlet

[ColOfAbRiX]

I added some basic structures in com.colofabrix.scala.figlet4s.control and I thin I will implement, at least for now, only the basic control commands because the extended command are only to handle special encodings of input.