Add .metadata to .gitignore
Fix bug in InternalMetadata.equals()

* Fix bug in project common, as has already been done in project
dataservice.
Add logging of Graph2D for debugging

* Add instance ID field mId in Node2D and Edge2D

* Add or improve toString() methods in Edge2D, Graph2D, Node2D,
NodeIdentifier2D, NodeMetadata2D

* Log Graph2D in JungCalculator.addRemoveNodesLinksMetadatas()
Fix bug: erroneous identification of different metadata entities

Background: A metatdata entity is until now identified by its type, its
properties (if present), and its timestamp. Since the timestamp has a
resolution of one second, it cannot be differentiated between metadata
of the same type and without properties (like device-ip) created in the
same second, leading to wrong graph layouts.
 
* Add class RichMetadata as a container for a metadata entity and its
corresponding identifier or link (depending on metadata type)
* Apply RichMetadata instead of Metadata in NodeMetadata, Connection,
PoolExpandedLink, PoolNodeIdentifier, PoolNodeMetadata

The graph layout remains to have bugs after this fix, e.g., in the
context of node deletion.
Minor changes: fix typos in comments, reset debug level to trace
Fix bugs in creation of identifier graph from JSON delta; add debug
information for delta

* Fix bugs in creation of identifier graph from JSON delta in
ProxyGraphService.insertIdentifierInto(): add new metadata and new links
to identifiers already present in identifier graph

* Add debug information for JSON delta in ProxyGraphService.parseJson()

* Add debug information for graph delta in
Connection.debugGraphContent()

* Minor changes: fix typos in comments
Add .metadata to .gitignore
Fix bug in InternalMetadata.equals()

* Fix bug in project common, as has already been done in project
dataservice.
Add logging of Graph2D for debugging

* Add instance ID field mId in Node2D and Edge2D

* Add or improve toString() methods in Edge2D, Graph2D, Node2D,
NodeIdentifier2D, NodeMetadata2D

* Log Graph2D in JungCalculator.addRemoveNodesLinksMetadatas()
Fix bug: erroneous identification of different metadata entities

Background: A metatdata entity is until now identified by its type, its
properties (if present), and its timestamp. Since the timestamp has a
resolution of one second, it cannot be differentiated between metadata
of the same type and without properties (like device-ip) created in the
same second, leading to wrong graph layouts.
 
* Add class RichMetadata as a container for a metadata entity and its
corresponding identifier or link (depending on metadata type)
* Apply RichMetadata instead of Metadata in NodeMetadata, Connection,
PoolExpandedLink, PoolNodeIdentifier, PoolNodeMetadata

The graph layout remains to have bugs after this fix, e.g., in the
context of node deletion.
Minor changes: fix typos in comments, reset debug level to trace
Fix bugs in creation of identifier graph from JSON delta; add debug
information for delta

* Fix bugs in creation of identifier graph from JSON delta in
ProxyGraphService.insertIdentifierInto(): add new metadata and new links
to identifiers already present in identifier graph

* Add debug information for JSON delta in ProxyGraphService.parseJson()

* Add debug information for graph delta in
Connection.debugGraphContent()

* Minor changes: fix typos in comments
Merge branch 'fixGraphLayout' of https://github.com/trustathsh/visitmeta into fixGraphLayout

Conflicts:
	.gitignore