ffmemless: Plugin for ff-memless vibra backend

Vibra plugin for kernel ff-memless type of force feedback event
device backend. Features include:
- effect setup from ffmemless.ini
- system level effect settings override from feedback.ini
- fall-back default effect in case of missing effect data
- configuration of policy from data/event.d/*.ini files by
  setting "ffmemless.effect" for each event which requires vibra
- play / pause / stop according to configured policy
- profile aware for "vibrating.alert.enabled" flag (no vibra
  playback if not enabled)
- replaces immvibe plugin as default "media.vibra" resource

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com>
ffmemless: Add basic effects for all events

Added new effects NGF_LONG, NGF_STRONG, and NGF_CLOCK
for ffmemless plugin.

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com>
ffmemless: Documented valid values for effect parameters

Wrote documentation comments to ffmemless.ini about the valid
parameter ranges and default values for ffmemless effects.

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com>
ffmemless: added effects for all required events

Added a basic setup of vibra effects for all events that had also
immvibe effects defined. The effects were tested on N9.

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com>