Statistics will now only be saved when scenario is stopped not each time when the LTM recording is disabled
Calculation of similarity/dissimilarity now also possible for more than two elements (still needs to be tested properly)

Functions for similarity calculation: MSE, MAE, Chernoff for NDArray objects
Information about experiments: statistics can now be generated and saved as JSON file when LTM recording is used

ltm/detail/MemoryBase: added functions to write statistics about the filter used to a JSON file when recording of the LTM is disabled
ltm/processors/Processor: added SnapshotSimilarityFilter as case and function to put statistics about used filters into map that can be accessed by other classes
ltm/processors/filter/Filter: added struct for filter statistics
ltm/filter/equalityFilter/EqualityFilter: changed accept() function to work with new similarity functions, holds a queue of images now and uses similarity functions in aron/similarity, also added to the configure() method because there are new parameters

ltm/filter/frequencyFilter/FrequencyFilter: added functions to get basic information for statistics
plugins/Plugin: added call to getFilterStatistics() to allow for saving of statistics in JSON file when scenario is stopped
test/ForgettingExperiments: added function to print information about filter and usage of those into a JSON file

aron:

similarity/../NDArraySimilarity: similarity function for NDArray elements (images)
similarity/../chernoff: calculates chernoff measure of two NDArray elements
similarity/../mae: calculates mae
similarity/../mse: calculates mse

Signed-off-by: uhfpm_plewnia <uhfpm@student.kit.edu>

# Conflicts:
#	source/RobotAPI/libraries/armem/server/CMakeLists.txt
#	source/RobotAPI/libraries/armem/server/ltm/base/detail/Processors.cpp
#	source/RobotAPI/libraries/armem/server/ltm/base/detail/Processors.h
#	source/RobotAPI/libraries/armem/server/ltm/base/filter/frequencyFilter/FrequencyFilter.h
#	source/RobotAPI/libraries/armem/server/ltm/detail/MemoryBase.h
#	source/RobotAPI/libraries/armem/server/ltm/detail/mixins/BufferedMemoryMixin.h
#	source/RobotAPI/libraries/armem/server/ltm/filter/similarityFilter/SimilarityFilter.cpp
#	source/RobotAPI/libraries/armem/server/ltm/filter/similarityFilter/SimilarityFilter.h
#	source/RobotAPI/libraries/armem/server/ltm/processors/filter/equalityFilter/EqualityFilter.h

Long-Term Memory changes

See merge request !342

ArViz: discarding layer updates if component name is empty

See merge request !343

Better handle case where robot is not globally localized yet (i.e., can be loaded but not synchronized)

This reverts commit 18db5c8a.

renamed aron converters, added new aron filters and similarity, added memory_conversions to make code look nicer

# Conflicts:
#	source/RobotAPI/libraries/armem_skills/CMakeLists.txt
#	source/RobotAPI/libraries/armem_skills/server/segment/ExecutableSkillLibrarySegment.cpp
#	source/RobotAPI/libraries/aron/similarity_measure/CMakeLists.txt

Merge branch '126-arviz-recording-record-full-initial-scene-in-first-revision-when-recording-is-started' into 'master'

Resolve "ArViz Recording: Record full initial scene in first revision when recording is started"

Closes #126

See merge request !339

Make point cloud in ARON work for PCL 1.8

See merge request !341