Test for #2727 (%run -m doesn't support relative imports)

test_run_submodule_with_relative_import fails.
Refactor part for "%run -t"
Support relative import in "%run -m"
Add a failing test for "%run -p -m ..."
Support relative import in "%run -p -m"
Add a failing test for "%run -d -m ..."
Support relative import in "%run -d -m"
Refactor part for "%run -d"
Fix ChangedPyFileTest.test_changing_py_file failure
Use list comprehension instead of filter+lambda
Add ExecutionMagics._run_with_profiler
Refactor ExecutionMagics._run_with_profiler
Rename ExecutionMagics._run_with_profiler argument
Document ExecutionMagics._run_with_profiler
Use UsageError for non-local exit + error message
Comment on "opts.merge" in _run_with_profiler
Fix %run usage line; mention -m and -e
Document private methods in ExecutionMagics
Sort imports in test_run.py
Merge pull request #3066 from tkf/run-module

Add support for relative import to %run -m (fixes #2727)