Nuke EC2 API from api-paste and remove wsgi support

Tempest has already removed the EC2 API tests in:
Ib5e24e19bcba9808a9f49fe7f328668df77fe4f9

We have a review in devstack below that removes EC2
API service by default.

In this review, we are removing support for the really
old EC2 API support in Nova. Anyone who needs EC2 support
should use the new EC2-API project:
http://git.openstack.org/cgit/openstack/ec2-api/

The necessary changes in Tempest and DevStack are
already merged.  In a follow on review, will remove
the EC2 specific options, code and tests from Nova.

DocImpact

Change-Id: Id7936be290b6febd18deb4c2db8ea4d678d4d9b1

setup.cfg

@@ -45,7 +45,6 @@ nova.image.download.modules =
 console_scripts =
     nova-all = nova.cmd.all:main
     nova-api = nova.cmd.api:main
-    nova-api-ec2 = nova.cmd.api_ec2:main
     nova-api-metadata = nova.cmd.api_metadata:main
     nova-api-os-compute = nova.cmd.api_os_compute:main
     nova-cells = nova.cmd.cells:main