Manual actions are accessible from:
- Pipelines
- Builds
- Environments
- Deployments

Feedback from:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4964#note_12867273

This method now should return false if build is not completed. If build
is running then it is not retryable, therefore `Ci::Build#retryable?`
returned wrong value. This commit changes this behavior

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4964#note_12744656

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4964#note_12741046

We store the sizes as a hash from path to bytes like:

``` ruby
{'ci_artifacts.txt' => 27,
 'other_artifacts_0.1.2/another-subdirectory/banana_sample.gif' =>
71759,
 'other_artifacts_0.1.2/doc_sample.txt' => 1314,
 'rails_sample.jpg' => 35255,
 'tests_encoding/utf8 test dir ✓/regular_file_2' => 7}
```

So that it's easier to access than reading gzip file again.

This reverts commit 13e37a3e.

This also moves tests from build_spec.rb to runner_spec.rb

This removes duplications and extracts method that builds build-jobs
without persisting those objects, to a separate method.

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

Use def with parentheses when there are parameters.

See #17478