Winet 6.50 released

Update notes

1. A Print Screen Preview facility has been added.
If RTF or Merge printing is selected for screen printing, the preview can make
the RTF editor available to edit the output before printing or to edit any RTF
file. This editor produces much cleaner RTF output than some other RTF editors.

2. RTF printing now supports Landscape and other paper attributes like paper size.

3. The latest OpenSSL version 1.1.0e is supported.

4. A problem with custom buttons when explicitly loading a new configuration has
been fixed.

5. Inet3270: NFT binary upload/download has been implemented for the 3270 emulation.

6. Inet3270: Occasional display of NFT screens has been fixed. In order to function correctly,
at least one history buffer must be specified in the 3270 setup.