tests: pass extra arguments given to run-tests.py into pytest.main()

incoming: save filename and line number for linter output in Check.lines

incoming: use dicts instead of tuples for Check.lines

models: add Project.get_title() method, use it, test it

incoming: parse_project_url() function to extract domain, user and name, tests

viewer: use a lineno class to put styles on the line number links

incoming: only try to match linter output if it's not a meta line

incoming: skip checking the whole line when it's linter output When a line starts with a certain pattern, it's recognized as linter output, but determining if it's an error or a warning was done looking at the whole string again multiple times. Let's save on regexes and look only on the important part.

viewer: inherit from BaseHandler for catch-all 404 pages too

viewer: templates for 404 and 500 error pages