Update _LANGUAGE_GUESS to include new languages

[JoelNiemela]

In addition to adding new languages, it also does the following changes:

• removes the entry '.h': 'C++',
• assumes the default version of JavaScript is Node.js (it previously guessed JavaScript, which is an invalid language name)
• assumes the default version of python is Python3 (it previously made no guess for .py files)

[simonlindholm]

assumes the default version of python is Python3 (it previously made no guess for .py files)

It did, actually, based on a heuristic:

kattis-cli/submit.py

Lines 129 to 161 in f5c31f3

	def is_python2(files):
	python2 = re.compile(r'^\s*\bprint\b *[^ \(\),\]]|\braw_input\b')
	for filename in files:
	try:
	with open(filename) as f:
	for index, line in enumerate(f):
	if index == 0 and line.startswith('#!'):
	if 'python2' in line:
	return True
	if 'python3' in line:
	return False
	if python2.search(line.split('#')[0]):
	return True
	except IOError:
	return False
	return False
	def guess_language(ext, files):
	if ext == ".C":
	return "C++"
	ext = ext.lower()
	if ext == ".h":
	if any(f.endswith(".c") for f in files):
	return "C"
	else:
	return "C++"
	if ext == ".py":
	if is_python2(files):
	return "Python 2"
	else:
	return "Python 3"
	return _LANGUAGE_GUESS.get(ext, None)

Kattis's submit page uses (used?) the same heuristic.