Relax Blob.getInstance() to allow null objectName

Glacier support uses this method to represent vaults, which
have a size but not object name. Currently @Nonnull only results
in IDE warnings but eventually we want violations to fail builds.
Merge pull request #79 from labisso/blob_annotation

Relax Blob.getInstance() to allow null objectName
Merge pull request #84 from TheWeatherCompany/develop

twc changes
Merge pull request #85 from TheWeatherCompany/windows-support

add ability to specify "reboot" or not when taking machine image
Merge pull request #86 from TheWeatherCompany/windows-support

new method to get instance password
Merge pull request #87 from TheWeatherCompany/SourceDestCheck

Add ability to create a "NAT instance" at launch.
Added support for various getVmState operations
Merge pull request #88 from andylyall/develop

Added support for various getVmState operations
Account for a separate subnetId in VmLaunchOptions
Merge pull request #89 from andylyall/develop

Account for a separate subnetId in VmLaunchOptions
Merge pull request #28 from greese/develop

Pull in upstream changes