Add ability to stream (and indent) command output
Refactor for simplicity, make the resource a stream
so that it is guaranteed to stick together or at
least not get anything else appended to it
Synchronize so that simultaneous prints do not
cross each other and mess up lines
Print prefix to distinguish separate streams of output
Fix unit test
Move output stream to its own class file
Make indentable print() function more intelligible
Allow command output to be indented in doc formatter