Create separate utils/graphics modules.

Add:
	src/utils.(c, h)
		-add generalized readFile() function, which reads a file and returns a
		ScannedFile_t struct with all of its content.
		-add ScannedFile_t definition, freeFile().

	src/interpreter/(file_parser, shell).c
		-replace blocks of code that handled file reading with a call to
		utils's readFile().
Mod:
	src/(utils -> graphics).(c, h)
		-rename current utils module to graphics, as it will contain functions
		used exclusively for graphics processing (rasterizing lines, rendering
		shapes, etc.), while utils.c will contain general utility functions.