[api] Implemented GET /resources/<property>/jobs

Example:
wget -O - http://localhost/oarapi/resources/network_address/jobs.yaml

api_timestamp: 1405523675
items:
  - jobs: []
    network_address: tchernobyl1
  - jobs: []
    network_address: node2
  - jobs:
      - 229
      - 230
      - 226
      - 228
      - 227
    network_address: tchernobyl2
  - jobs: []
    network_address: node1
  - jobs: []
    network_address: fukushima1
  - jobs: []
    network_address: fukushima2
links:
  - href: ../..//resources/network_address/jobs
    rel: self
[drawgantt-svg] fix warning for syntax error

callback must be given as string
[drawgantt-svg] add support to display "resource draining"