ffmemless: Add repeat support

Added repeat support for ffmemless plugin. Also fixed the playback done reporting on single shot effects + other minor changes.

Kalle Jokiniemi (6):
  ffmemless: fix ffm_get_int_value return value on NULL
  ffmemless: Add debug for ffm_get_int_value
  ffmemless: Add effect repeat support
  ffmemless: Add specific effect for SMS
  ffmemless: Document system settings file usage
  ffmemless: Tune STRONG, BATTERYLOW and CLOCK effect parametes

 data/events.d/sms.ini          |    2 +-
 data/plugins.d/ffmemless.ini   |   54 +++++++++++--
 src/plugins/ffmemless/plugin.c |  175 ++++++++++++++++++++++++++++++----------
 3 files changed, 180 insertions(+), 51 deletions(-)