This is the first commit in a series of commits
which improve the readability of some of the code
and add tests.

File: base64.js
Tests Added: True
Changes:
- Improved indentation
- Fixed JSHint errors
- Moved loop variables to be declared in the loop for better readability
  (N.B. Javascript does not have block scoping, so the variables are
  still technically available outside the loop -- it just makes the code
  clearer to place them inside the loop, since they are only used there)