allow requesting a set of resources from a specified pool

If the number of resources is a positive integer, the job will try to
reserve N resources among the specified ones.

The reserved resources names will be stored in a build variable whose
name is specifiable in the job configuration.

Signed-off-by: Aki Asikainen <aki.asikainen@kone.com>
Signed-off-by: Robin Jarry <robin.jarry@6wind.com>
allow manually reserve/unreserve resources in the lockable resources panel

All logged-in users are allowed to reserve free resources. A resource
can only be unreserved by the user that reserved it or by an
administrator.

Signed-off-by: Aki Asikainen <aki.asikainen@kone.com>
Signed-off-by: Robin Jarry <robin.jarry@6wind.com>
[maven-release-plugin] prepare release lockable-resources-1.1
[maven-release-plugin] prepare for next development iteration
add new "reserve" and "unlock" permissions for lockable resources

In order to be able to reserve, unreserve or unlock resources, the user
must now have these permissions granted.

Signed-off-by: Robin Jarry <robin.jarry@6wind.com>
[maven-release-plugin] prepare release lockable-resources-1.2
[maven-release-plugin] prepare for next development iteration
Allow requesting one resource from a set of resources
Add a new option to store reserved resources in a variable
Fix documentation
Remove unnecessary log printing
Make the amount of required resources configurable, fix indentation
Add possibility to
- manually reserve a resource
- unreserve a resource reserved by the same user
Fix indentation, again