Application Kata "Convert roman"

Write a console application that can be used to convert Roman/Arabic numerals. The following example shows possible calls:

$ convertroman XLII
42
$ convertroman MMXV
2015
$ convertroman 2015
MMXV
$

The number to be converted, either Roman or Arabic, is passed as a command line parameter. The result is displayed on the standard output of the console. The application automatically recognizes the direction in which the number must be converted.

Only Roman numerals in the range from I to MMM need to be taken into account.

Variation #1

The user can specify a text file as a parameter of the command line, as the following example shows:

$ convertroman -f=numbers.txt
XLII
2015
$

Contents of the numbers.txt file in this example:

42
MMXV

Resources

[1] Wikipedia, Roman Numerals, https://en.wikipedia.org/wiki/Roman_numerals