mate-applets-1.5.2: Version bump + remove patch + use libnotify

Version bump to 1.5.2
Release now includes commit that enabled gucharmap [1]
Now uses x11-libs/libnotiy [2]

[1] https://github.com/mate-desktop/mate-applets/commit/79c1485d955e32a1d2fc64e96f8b342c76be3f4f
[2] https://github.com/mate-desktop/mate-applets/commit/41389eb9c8c16917cbc4060b3769da95ecb64dd1