Add pseudo-tty support for openssh calls via starcluster.
Merge branch 'hotfix-0.94.2'
Raise an exception if min_nodes > max_nodes in loadbalancer
Fix loadbalance to add nodes when below min_nodes
Merge pull request #310 from datacratic/loadbalance_min_max_compare_exception

Raise an exception if min_nodes > max_nodes in loadbalancer
loadbalancer: consolidate num_nodes in _eval_add_node
Merge branch 'fix-min-nodes-check' into develop

closes gh-311
use pycrypto to compute pub/priv rsa fingerprints

* Replace pyasn1 with PyCrypto as a direct dependency of StarCluster
* Deprecated SSHClient.{generate_rsa_key,get_public_key} in favor of
  sshutils.{generate_rsa_key,get_public_key}
cluster: validate imported keypair fingerprints
awsutils: add import_keypair function

Takes an existing RSA public key and uploads the public material to EC2
via the ImportKeyPair API.
awsutils: raise exc if keypair exists in create_keypair
awsutils: use 'as' everywhere when handling exceptions
commands: add _file_exists callback to CmdBase

The callback expands the path, converts it to an absolute path, and then
verifies that it 1) exists and 2) is a file.
createkey: add --import-key option

This option allows importing an existing RSA key as a new EC2 key rather
than having EC2 autogenerate and return a new RSA key.
Merge branch 'keypair-utils-improvements' into develop
Fixing typo
Merge pull request #317 from edwardsp/develop

Fixing typo
add support for new GRID GPU g2.2xlarge (non-GPGPU) instance type
volume: fix for reporting duplicate vol hosts
node: fix deprecation warnings from sshutils