Merge branch 'validation_fix_renderpass' into 'vulkan-cts-1.0-dev'

Merge branch 'validation_fix_renderpass' into 'vulkan-cts-1.0-dev'

Validation fixes for dEQP-VK.renderpass

- Correct access flags in layout barriers
- Remove duplicate barrier
- Don't do layout transition if src and dst are the same
- Fix minDepthBounds value

Note, this does NOT fix all the issues with this test group. I'm getting many problems with `dEQP-VK.renderpass.attachment_allocation.*` mainly due to operations on undefined memory, or attachments not included in a subpass.

See #357 for other validation tasks.

See merge request !536