Police in Kensington, New Hampshire, say a man who threatened to commit suicide through Facebook Messenger and displayed a gun via Skype caused officers to go to his home to check on him.    Police surrounded the home early Friday. The man, identified as 19-year-old Timothy Curtis, appeared at a door brandishing a revolver-style handgun, then went back inside. He eventually left, unarmed, with his mother, 57-year-old Lauren Curtis. He was released to the custody of Exeter Hospital personnel for a mental health evaluation.    Inside, state troopers found Timothy Curtis' father, 62-year-old Gregory Curtis. Troopers found a .22-caliber handgun on the living room couch and a loaded .25-caliber handgun in a bedroom. The guns, along with multiple machete and military-style knives, were seized from the home during a consent search.