FIX: crash in shell command when ipcluster_dir already exists
Fixed an issue of bad errors messages due to plugins
Fixed bad call
Refined err msg
Merge pull request #200 from ogrisel/ipshell-existing-ipcluster_dir

FIX: crash in shell command when ipcluster_dir already exists
scimage: add liblapack-dev to default pkg list
Added debug logging
Draft ipcluster plugin refactoring to drop SGE requirement.

The NFS partition is used instead to be able to run:

    ipcluster engines -n numproc

on each non-master node of the cluster.
add timeout when fetching json file + simpler cluster shutdown
Use the cluster thread pool to start the engines on the nodes
add support for new cr1.8xlarge instance type
node: fix bug in Node.get_device_map()

Devices can be attached to EC2 instances with a partition naming scheme,
e.g. /dev/xvdb1, instead of the traditional device naming scheme, e.g.
/dev/xvdb. Updated Node.get_device_map to include these devices.
node: fix bug in Node.get_partition_map()

Updated regex used to parse partitions from 'fdisk -l' output to ignore
a '+' character that may or may not be appended to the partition's block
value, e.g. 80230823+

Also updated regex to match the obscure case of a partition within a
partition. These partitions usually look like: /dev/xvdb1p1,
/dev/xvdb1p2, etc.
Merge branch 'fix-device-partition-maps' into develop

closes #205
cli: show traceback for ALL THE UNCAUGHT AWS ERRORS!!

Updated the boto exception handling code to always dump the full stack
trace straight to console. This way we actually stand a chance of coming
up with a fix for random AWS errors.
node: regex fix in Node.get_partition_map()

Ignore all trailling + or - chars, if any, on the start, end, and block
values from 'fdisk -l'.
cluster: fix bug in load_receipt related to spot

Only wait for the master node to appear in load_receipt() if there are
unfulfilled spot requests (ie those without an instance_id associated
with them). This causes the code to properly reraise the
MasterDoesNotExist exception in the case that all of the cluster's spot
requests have been fulfilled and there is no master node to be found.
Using log instead of traceback
Fix refactoring
Using logging instead of traceback.
Moved the getattr call within get_plugins to the existing try and moved the execpt there as well.
Merge pull request #201 from datacratic/plugins_confs_fixes

Fixes 2 issues related to loading plugins