stbt.py: pylint and pep8 compliance fixes

stbt.py:337: [W0301] Unnecessary semicolon
stbt.py:916: [E1101, _match_template] Instance of 'Position' has no 'y' member
stbt.py:917: [E1101, _match_template] Instance of 'Position' has no 'x' member
stbt.py:224:17: E126 continuation line over-indented for hanging indent
stbt.py:227:13: E123 closing bracket does not match indentation of opening bracket's line