fix missing-field-initializers warnings
fix redundant-decls warnings
fix implicit-function-declaration warnings
take over changes from LocutusOfBorg/fix-warnings
fix remaining warnings in GTK UI
fix unused-variable warnings
fix unused-function warnings in ND poisoner
fix empty-body warning
fix warninigs in fraggle_attack plugin
fix unused-function warnings in etterfilter
fix redundant-decls in etterfilter
Merge pull request #437 from koeppea/fix-warnings-top2

Fix warnings