use 'errors' repository for defining cc errors

for adding/modifying errors, modify this repository. this makes it much
easier for ccng and client libraries (i.e. cfoundry) to stay in sync.
remove lower-level error definitions

merge VCAP::CloudController::Errors and VCAP::RestAPI::Errors into
VCAP::Errors

add VCAP::CloudController::Errors alias so everything doesnt have to
change
fix Error constant lookup to be scoped under VCAP
"make it work" - tim gunn
change InvalidAuthToken error code to 1000
minor refactor to app_bits_spec

Change-Id: Ic0016dd0010f5407c608710f821abd76c3f13832
do not require zip file when updating bits

Change-Id: I7edaab5b76c58a8a40180f0307c0208ec4b1281c
[fixes again #44321011] Move space_summary_endpoint to be more consistent with nested structure
Set app state to failed when uploading the package fails [#41992297]
Check for empty package_hash before staging apps [finishes #41992297]
Initial stab at a Stack model.

Change-Id: Idfdb3850261b211f69b6890f192bc8047dc98005
added directories.stacks config option

Change-Id: Ib0606b51195f67addc33affc31f4013bee5b6c57
populate stacks table with stacks from config directory

Change-Id: I0d8aed1f0683ad24ddd95e06d736f0f5c2c9db70
Add a read-only option to shared examples; if provided we will assert that
those endpoints are not accessible.

Change-Id: I40d07a191df6763c7ce9269976989351d017b981
Honor read-only option on invalid object shared examples.

Change-Id: Id2ea4adfb38e72b795c11bcccb13914167404b1a
Support REST controllers for models that do not have relationships.

Change-Id: I2bca0b95e8e4fd9b9e3a39db0d49b86e67eedbc1
Expose stacks in v2 API.

Change-Id: Id8b0ad6f3c9bba85f84ca93e1dd0fd1944f9d7af
formatting

Change-Id: Id7a0a03ebebe4fd3d3dbbd4d999083cf929279e5
use single yml file for configuring stacks

Change-Id: I6e04abbc8acbc1015fc9c29f60d0676c76840a42
validate stacks config files

Change-Id: Ie9345491d7ea22a80088bfa170bf8d6183749e6b