Return true
if string str is US telephone number, false
otherwise.
US telephone numbers look like these:
'555-555-5555',
'(555)555-5555',
'(555) 555-5555',
'555 555 5555',
'5555555555',
'1 555 555 5555',
'1 (555) 555-5555',
'1(555)555-5555',
'1 456 789 4444'
But not like these:
"1 555)555-5555",
"555-5555",
"5555555",
"123**&!!asdf#",
"55555555",
"(6054756961)",
"2 (757) …