Rename 'binary' directory to 'binary-dist' (#43)

Rename 'binary' directory to 'binary-dist' (#43)

* Rename 'binary' directory to 'binary-dist'

Debian invokes a 'binary' target in its build process. The presence of
the 'binary' directory breaks the automated build, as 'make' thinks the
target has already been invoked.

* Use substitution variable for 'mkdir -p' instead of hard-coding the command