[fix #156] Fix regression in paper option

The fix is quite simple, the problem is real however. The role saving
function must be actually executed for the roles to be persisted into
the database.

This bug only impacts the paper options screen, contributors can still
be added or removed by using the new "Share" menu in the paper editor.
Merge pull request #158 from satabin/fix/156-cannot-add-contributors

[fix #156] Fix regression in paper option
[#161] Add report issue and clone link in the configuration

Add two new optional configurations:
 - blue.client.issues-url: link to report issues
 - blue.client.clone-url: where the code can be found.

The client side configuration manager has been improve.
All configurations stored in AppConfig is now automatically available in the constant
config.
Merge pull request #164 from tdurieux/config-report-url

[#161] Add report issue and clone link in the configuration
[fix #155] Avoid overwriting configuration

When the installation script is invoked, it first checks that the places
where files are about to be installed are free. If directories already
exist, just abort installation.
[imp #155] Add installation upgrade script

This is a quite simple script which won't handle all cases but should be
able to upgrade from installations made with the provided `install.sh`
script.
Merge pull request #167 from satabin/feature/upgrade-script

Feature/upgrade script
Add changelog
Merge pull request #169 from gnieh/v1.0.x

Merge changes from V1.0.x branch