mate-power-manager-1.5.2: Version bump + use libnotify + systemd-inhibit

This version now depends on >=libnotify-0.7.0 [1]
Add systemd inhibit support (use flag + config option)

[1] https://github.com/mate-desktop/mate-power-manager/commit/d39dce39122b4f2e02c5e169581daa9016d26bfc