keep leading zeros in front of numbers

[kdauer]

Problem to solve

As Squeak Developer, I want to keep leading zeros in front of my numbers so that bit patterns and every number is maintained.

Further details

relates to #32

Acceptance Criteria

• Writing numbers and bit patterns in Squeak. Given leading zeros in front of numbers, when Poppyprint is formatting those numbers, then leading zeros are kept.
• Bitstrings should be like this code example and the zeros in front are kept:

Bit 000111100101