Merge branch 'release/0.12.5' into develop
Improve exception handling when trying to send back job results.
Make heartbeat start before fetching input to prevent invalid crash detection.
PEP8 compliance in job.py
Made examples executable
Tweak examples to use multiprocessing when drmaa isn't available.

- Also make manual and map_reduce calculate the same values
Add comment to map_reduce.py
Update copyrights
Switch to 3.4 for travis Python 3 builds
Enable INFO-level logging in examples to help people understand how things work
Add some debug and info level output to job.py
Disable system site packages on Travis
Add info about the queue keyword argument to examples.
Fix #35
Switch to importlib instead of __import__.

Also added psutil requirement to README and linked to pythongrid repo.
Fixes #34
Move job name out of native specification for improved non-SGE compatibility.
Fixes #26
Bump version to 0.12.6
Bump version to 0.13.0, since there are more than bugfixes in this release.