FMSLogo Code

Document the breaking change to BACKSLASHEDP

Merge in changes from trunk (mostly to resolve conflicts)

Update the documentation for CHAR, ASCII, and RAWASCII for Unicode support.

Set up the release notes for v7.7.0, in case a bug fix is needed before v8.0.0 is ready.

Fix a misspelling of "Devuelve"

Mark that trunk has been merged into this branch.

Add a UTF-8 BOM when using SAVE, since po() will use UTF-8.

Remove references to signed/unsigned wchar_t by casting to int.
This was done to work around a bug in gcc-9.2.1.
While the bug has been fixed upstream, it has not yet come to Fedora 30.

This is not the way I wanted the code, but it's better than not being able to compile at all.

Merge in changes from trunk.
This was done to get the changes that pass a stream to po_helper.

Fix a typo in a test prompt.