Code completion, highlighting and std stream redirections

[tkf]

This PR implements:

• Code completion for line and cell magics by monkey-patching IPython. closes Add IPython completion hook in julia.magic #193
• Code highlighting in terminal (not in Juypter) by monkey-patching IPython
• Redirection of Julia's stdout and stderr to Python's output streams. It is usable only in ipykernel (Jupyter) at the moment. closes Redirect julia STDOUT to python sys.stdout? #49

[coveralls]

Pull Request Test Coverage Report for Build 612

• 92 of 125 (73.6%) changed or added relevant lines in 6 files are covered.
• 6 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+1.4%) to 57.797%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
julia/core.py	6	7	85.71%
julia/magic.py	29	31	93.55%
julia/ipy/monkeypatch_interactiveshell.py	20	24	83.33%
julia/tools.py	4	10	40.0%
julia/ipy/monkeypatch_completer.py	30	50	60.0%

Files with Coverage Reduction	New Missed Lines	%
julia/core.py	6	55.53%

Totals
Change from base Build 606:	1.4%
Covered Lines:	656
Relevant Lines:	1135

---

💛 - Coveralls