Placeholder support in audience attribute

SKILL EXAMPLE

testaudiencetargeterradius:
 Skills:
  - setvar{var=skill.test;t=STRING;v=@PIR{r=50}} @Self
  - particles{p=flame;a=100;s=0.3;audience=<skill.var.test|@Self>;repeat=19;repeatI=10} @Forward{f=10;lockpitch=true}