Holding an injunction banning picketing was "justified only by the violence that induced it and only so long as it counteracts a continuing intimidation"
Concluding that "when the entire record is considered there was substantial evidence to support the Board's finding that [employee's] discharge was the result of his having presented a grievance to the management" even though employee was overheard referring to company's superintendent as "the horse's ass" and was thereafter summarily discharged