app-i18n/uchardet: rename from dev-libs/uchardet

app-i18n/uchardet: rename from dev-libs/uchardet

Rationale:
- provided functionality better fits app-i18n/ category;
- uchardet is similar to existing app-i18n/enca and app-i18n/libguess;
- uchardet also provides CLI tool, not only a library.

Checklist:
1. `git mv dev-libs/uchardet app-i18n/uchardet`                ✓
2. Add entry to profile/updates/1Q-2017                        ✓
3. Update reverse dependencies                                 ✓
4. Update entries in profiles/                                 ✓
5. Update eclasses that reference the package (there's none)   ✓
6. Update metadata.xml entries that reference the package      ✓
7. Update news items that reference the package (there's none) ✓

Gentoo-Bug: https://bugs.gentoo.org/593176