Changes made for YAML input - GSoC18

[MaidouPP]

This PR includes necessary changes for accepting YAML annotator input, so that users can provide pure YAML annotators, and RoboSherlock will take care of the conversion to xml and so on.

The temporary xml file will generate under .ros/generated_xmls folder. The example YAML files are in annotators/io/yaml/CollectionReader.yaml and annotators/segmentation/yaml/PointCloudClusterExtractor.yaml. You can test it with u_test AE, which includes both of the CollectionReader and PointCloudClusterExtractor.

[bbferka]

@MaidouPP before I start reviewing please re-open the PR to the devel branch and not master; Edit: nevermind, I could change the base;

[bbferka]

@MaidouPP tests fail because only RSControledAE class has the yaml parsing but not the RSAnalysisEngine parent class; We need to change this; The test use the RSAnalysisEngine class for now; The delegat parsing xml generation should happen in RSAnalysisEngine (I am considering merging these two classes, or at least refactoring parts of the code since it's becoming quite confusing ); Also because this is the base class for RSAE execution (I will rename this to something like RSAAEProxy since that reflects more it's functionality)

[MaidouPP]

Need to switch to another base branch and re PR.

[bbferka]

@MaidouPP I merged some changes from devel; please pulland fix; left a TODO fin RSControlledAE for yoy