Disable display timeouts for emulator

Bug #575.
Signed-off-by: Nikolay Nizov <nizovn@gmail.com>
Instead of checking for the defines TARET_DESKTOP or TARGET_EMULATOR do that with

Settings::LunaSettings()->hardwareType == Settings:HardwareTypeEmulator ||
Settings::LunaSettings()->hardwareType == Settings::HardwareTypeDesktop

at runtime (for reason see comment above).

See https://github.com/webOS-ports/luna-sysmgr-common/blob/webOS-ports/master/include/Settings.h#L298