Minor explorer tuning

[eputtone]

1. Add hooks for customizing Explorer look through config.js (header logo, hide footer, change HTML title)
2. New look for workflow instance properties (previous made your eyes bleed). Also changed the order a bit and removed redundant workflow instance id (it was shown after workflow definion name already)
3. Layout of workflow instance properties and graph changed. Usually everything (properties, graph, tabs) fit "on the same line", but for large workflows (>15 states) rendering remains as it was (graph below workflow instance properties)
4. Separate ugly link from workflow instance page removed and workflow type name converted to a link.

[coveralls]

Coverage increased (+0.005%) to 80.941% when pulling 39e5615 on minor-explorer-tuning into 78a48a3 on master.

[coveralls]

Coverage remained the same at 80.936% when pulling 55dd743 on minor-explorer-tuning into 78a48a3 on master.

[efonsell]

Changelog?