Update to the current release of rply, 1.1.4

[musicinmybrain]

Update the bundled copy of rply from 1.01 to 1.1.4, and adapt the call to ply_open() in ply.cpp.

(I am considering packaging this for Fedora Linux, and I would want to build it using an external/system copy of the rply library rather than with the bundled copy. API-compatibility with the current release is a prerequisite for that.)