Fix typo
Return only the elarm_servers, not the elarm_registry
Add additional supervision level on top of elarm servers...

... in order to move the 'which_servers' function down from elarm_sup,
as elarm_registry:init cannot invoke elarm_sup:which_servers - or it
gets stuck.
HACK Add Rebar binary
HACK Call rebar in current directory - not in path
HACK Commit PLT for Dialyzer