Gridmap

This release includes several bugfixes and improvements made by dan-blanchard and andsor, including using the latest `psutil` API and support for the `-pe` (parallel environment) option.

Fixes:
- Remove ETS-specific path cleaning code (35)
- Module paths are now prepended to `sys.path` instead of appended (26)
- Made `JobMonitor` more resilient to SMTP settings problems (34)

Improvements:
- Improve exception handling when trying to send back job results.
- Heartbeats start before fetching input to prevent invalid crash detection
- Test against 3.4 instead of 3.3 on Travis
- Updated copyright notices to say 2014
- Add INFO-level logging messages about how jobs are running
- Switch to using `importlib` instead of using `__import__`
- Job name is no longer set using DRMAA native specification and instead uses `JobTemplate.jobName`.

Fix issue where `_process_jobs_locally` would not work with `max_processes > 1`

- Added `max_processes` argument to `grid_map` function for consistency.

Fixes `local` mode fallback when DRMAA Python isn't available.

Just fixed a couple minor issues.
- `exception` is now the properly set as the cause of death when a job encounters an exception.
- Fixed a potential memory leak in the `qmaster` process caused by not cleaning up job info as recommended in the [DRMAA Python documentation](http://drmaa-python.readthedocs.org/en/latest/tutorials.htmlwaiting-for-a-job).
- Changed default `session_id` in `JobMonitor` to `None` to be more Pythonic, instead of -1 like it was before.