Update CHANGELOG
builder/amazon/common: support user_data_file
builder/amazon/all: support user data file
website: document user data stuff
builder/amazon/common: retry deleting security group [GH-278]
builder/amazon/common: correct logic in deleting secutiry group
v0.3.0
builder/vmware: fix windows builds
Up version for dev
packer: replace stdout/stderr after StartWithUi

This just kind of shields the error with StartWithUi if we retry
communicator/ssh: fix panic when client is nil on reconnect
provisioner/shell: start_retry_timeout for reboot handling [GH-260]
Merge remote-tracking branch 'upstream/master'