Added getters for Shape bounding boxes.
Separated Rectangle's ps function implementation from declaration.
Added bound setters to Shape.
Added bounding box to Rectangles.
Wrote some Rectangle tests.
Made bound-box setters private.  Should only be set by class methods.
Hid sanity check (still runnable if called explicitly). Made some cosmetic changes.
First whack at our PostScript printer.
Wrote some sample code for the printer.  Changed print() to separate object output with newlines.
Added some includes to polygon.
Converted string Printer into a Shape printer.
Replaced std::move with move and a 'using'.
Made Rectangle's PostScript function use an ostringstream.
Added some Printer comments.
Wrote a flush() member function for Printer.
Renamed StdoutPrinter identifier to printqueue.