Bump shared library versions after ncurses bump in 13.

[jhb]

Summary

A few shared libraries in the base system link against ncurses. An
upgrade from a 12.x host to 13 results in ABI breakage for existing
binaries since the newer versions of these libraries link against the
newer ncurses while the binary itself links against the older ncurses.
For example, dialog4ports built on 12.x crashes on 13 since it depends
on libdialog which links against ncurses internally.

[jhb]

Hmm, this will also need ObsoleteFiles.inc updates. Also, the misc/compat12x packages need updating (they are already missing the old lib{form,menu,panel}.so.5 libraries now).

[jhb]

I was wrong, btw, 12.x includes wide versions of form/menu/ etc. so those have to be bumped to 6.

[jhb]

• Add libedit and ObsoleteFiles.inc entries.

[delphij]

I was going to propose the same change so LGTM. Leaving releng as-is for now just in case someone from re@ wants to chime in.