Rename "repo_type" attribute of the repositories scope to "type"

When the scope was initially implemented we were running on Ruby 1.8 and
"type" conflicted with Object#type so we had to name the attribute
differently. Since we're only supporting Ruby 2+ now "type" can be used
instead.
Improve data format of "users" scope

Integers are stored as integers now and names are more consistent and
descriptive.
Improve data format of the "groups" scope

The gid is stored as an integer now instead of a string.
Get rid of package_file_flag attribute in changed-managed-files scope

It isn't used anywhere anyway.
Merge pull request #57 from SUSE/review_140808_improve_changed_managed_files_data_format

Get rid of package_file_flag attribute in changed-managed-files scope
Merge pull request #56 from SUSE/review_140808_improve_data_format_of_groups_scope

Improve data format of the "groups" scope
Merge pull request #55 from SUSE/review_140808_improve_users_data_format

Improve data format of "users" scope
Merge pull request #54 from SUSE/review_140808_rename_repo_type_to_type

Rename "repo_type" attribute of the repositories scope to "type"
Fix UsersRenderer. The "info" attribute was renamed to "comment"

See commit 1568473 for reference.
Merge pull request #61 from SUSE/review_140811_fix_users_renderer

Fix UsersRenderer. The "info" attribute was renamed to "comment"
Adapt general logic to use underscores for JSON scope names

The inspector, renderer and system_description classes were adapted to
use underscores a separators for JSON scope names.
The usage of the the command line scope names wasn't changed though,
they still use dashes as separator.
Adapt unmanaged-files logic to use "_" for JSON

The unmanaged-files logic was adapted to use underscores as separators
for JSON scope names.
The usage of the the command line scope names wasn't changed though,
they still use dashes as separator.
Adapt config-files logic to use "_" for JSON

The config-files logic was adapted to use underscores as separators for
JSON scope names.
The usage of the the command line scope names wasn't changed though,
they still use dashes as separator.
Adapt changed-managed-files logic to use "_" for JSON

The changed-managed-files logic was adapted to use underscores as
separators for JSON scope names.
The usage of the the command line scope names wasn't changed though,
they still use dashes as separator.
Replace repeated Inspector.all_scopes call by attribute
Add convert_scope_names class method to CLI

Since scope names are now stored with an underscore internally we need
to convert them if we provide information about scopes to the user.
Convert scope names before showing them to the user

Since the internal scope naming scheme now differs from the command line
one the scope names need to be converted when presented to the user.
Incorporate suggestions