symbols/se: replace duplicated upper-level symbols with semi-useful ones

This especially replaces the § symbol on the fourth level of AD02 because it already exists on the first level of TLDE, which makes it somewhat likely to be used in a shortcut, which can lead to the other symbols on AD02 getting filtered out in some desktop environments.

(The latter is of course a problem in those desktop environments, but there's is no harm in preventing the problem from occurring by eliminating the duplicate symbol.)

It further replaces a duplicated ¢ with ‰, a useless ⅝ with √ (because ⅛, ⅜ and ⅞ are absent), a duplicate @ with ω, a useless ſ with σ, the duplicated § with Σ, a duplicate ® with ™, two duplicated thorns with π and Π, a duplicated & with †, a duplicate © with 🄯, and a duplicate dead abovedot with ….

This fixes issue #388 (closed).

Reported-by: Markus Hartung

Signed-off-by: Benno Schulenberg bensberg@telfort.nl