Qwt 5.2.1

Qwt 5.2.1 has been released.

Qwt 5.2.1 is a maintenance release with a couple bug fixes. It should be binary
compatible with Qwt 5.2.0 on most platforms, but I'm not 100% sure about
Windows because some pointless declarations for exporting templates have been
removed from the headers.

In opposite to earlier releases I have also uploaded the documentation as .qch file, that can be loaded into the assistant.

Qwt 5.2.1 is available from the Qwt project page: https://sourceforge.net/projects/qwt/files/

Uwe