Add load balancing service endpoint to eucarc - EUCA-5594

A AWS_ELB_URL environment variable is added for load balancing clients.

EUCA-5594
Load balancing SOAP pipeline namespace updated - EUCA-5426

The service namespace is updated to match the one used in the binding.

EUCA-5426
SOAP namespace prefix compatibility change - EUCA-5416

SOAP responses no longer use a prefix for the SOAP envelope namespace
for improved client tool compatibility.

EUCA-5416
Signature V2 request path compatibility change - EUCA-5416

Signature V2 support is updated to allow for clients that incorrectly
canonicalize the request by lower casing the path and skipping the last
"/".

EUCA-5416
PEM private key credential now PKCS#8 format - EUCA-5416

The format of the PEM private key in the downloaded credentials Zip file
is now PKCS#8 format for better tool compatibility. This is referenced
by the EC2_PRIVATE_KEY environment variable.

EUCA-5416
Auto scaling EBS optimized in create launch configuration - EUCA-5416

Creation of a launch configuration now allows the EBS optimized option
to be specified in SOAP requests.

EUCA-5416
Euare PEM private key now PKCS#8 format - EUCA-5416

The format of the PEM private key output from euare-usercreatecert is
now PKCS#8 format for better tool compatibility.

EUCA-5416
EUCA-5658 Fixed "cloudwatch put metric data queue can lose data", simplified
the put metric data queue.
EUCA-5662: custom authorization for loadbalancer VM requests
  -- IAM role credentials are used for message authentication purposes
  -- we do not use IAM policy for the authorization because
    1) the internal role should be able to lookup system wide instances and loadbalancers
    2) role delegated from loadbalancer's owner is not how AWS implements
  -- the custom authorization rule checks the source ip of the request, and authorize only when the source ip maps to one of loadbalancer VM
EUCA-5420, EUCA-5421: enable and disable availability zones
-- new loadbalancer can be created without any zones specified (appears that AWS require at least one zone specified, which is ok)
-- enable/disable-availability-zone update the ASG with the updated zones
-- the state of servo instances are updated accordingly (e.g., disabling zone will retire all servo instances in a zone)
-- the state of backend instances are updated accordingly (disabling zone will make them OutOfService state)
    EUCA-5672.  Extra dimensions being listed for system metrics.  To fix this, dimension folding is limited for 'AWS/EC2' metrics to subsets of at most one element.  Other system metrics are fully folded
Merge branch 'team/clc-dev/services' into testing