Cross-platform udevadm_settle

RHEL doens't have /sbin/udevadm. Call /sbin/udevsettle instead.
Use native method instead of shelling out
Fix typo in comment
Use df's POSIX output format

so that a mount point doesn't go to multiple lines
Prefer Bosh::Exec when shelling out
fake aws stemcells

- allows use of existing AMIs in a director
BAT_DNS_HOST is not optional
AWS script should not remove protected instances resources [fixes #44549997]
Fix spec:system:aws
Convert tabs to whitespace
example usage of blobstore_client_console
Fix failing bat manifest specs
[finishes #44595437] allocate an extra elastic IP for the DEA in dev/test
Merge pull request #46 from drnic/remove_tabs

Convert tabs to whitespace
Merge pull request #47 from drnic/blobstore_client_example

Example usage of blobstore_client_console
Update blobstore_client gemspec for renamed README & example config [fixes #49]
Merge pull request #49 from drnic/blobstore_client_example

blobstore_client.gemspec had a hardcoded reference to deleted README file
remove trivial whitespace
Merge pull request #50 from drnic/remove_trivial_whitespace

remove trivial whitespace
use sigar instead of sys-filesystem