Test selection syntax is baroque and foreign

When I want to run a single test, I have to use an odd double-colon syntax:

$ pytest tests/test_api.py::ReportIncludeOmitTest::test_include

Double-colons appear nowhere in Python. If the test fails, pytest even reports the failure to me using the usual single-dot syntax:

=================================== FAILURES ===================================
______________________ ReportIncludeOmitTest.test_include ______________________

Please allow the more usual single-dot syntax, and perhaps a single colon between file and class?

$ pytest tests/test_api.py:ReportIncludeOmitTest.test_include

Versions:

$ pytest --version
This is pytest version 3.0.5, imported from /usr/local/virtualenvs/coverage/lib/python2.7/site-packages/pytest.pyc
setuptools registered plugins:
  pytest-xdist-1.15.0 at /usr/local/virtualenvs/coverage/lib/python2.7/site-packages/xdist/boxed.py
  pytest-xdist-1.15.0 at /usr/local/virtualenvs/coverage/lib/python2.7/site-packages/xdist/looponfail.py
  pytest-xdist-1.15.0 at /usr/local/virtualenvs/coverage/lib/python2.7/site-packages/xdist/plugin.py
  pytest-warnings-0.2.0 at /usr/local/virtualenvs/coverage/lib/python2.7/site-packages/pytest_warnings/__init__.pyc

Start at pytest's command-line test-selection entry point and compare the current double-colon syntax with the proposed single-dot and single-colon forms shown in the issue. Done means the proposed selectors work while existing syntax remains supported, with failures reported consistently.