BEIJING/KATHMANDU, Jan 7 (Reuters)- A powerful earthquake struck the foothills of the Himalayas near one of Tibet’s holiest cities on Tuesday, killing at least 126 people and flattening hundreds of houses, Chinese authorities reported. The 6.8-magnitude quake’s epicenter was approximately 80 km (50 miles) north of Mount Everest, the world’s highest peak. Tremors shook buildings...