Merge tag 'v1.5.5'

CONTRIBUTING.md

general/docs/contributions.md

org.lamport.tla.toolbox.doc/html/model/about-models.html

org.lamport.tla.toolbox.doc/html/model/advanced-page.html

org.lamport.tla.toolbox.doc/html/model/creating-model.html

org.lamport.tla.toolbox.doc/html/model/executing-tlc.html

org.lamport.tla.toolbox.doc/html/trouble/trouble.html

...mport.tla.toolbox.doc/html/update/update-preferences.html

org.lamport.tla.toolbox.doc/pdfs/SRC-TN-1997-006A.pdf

org.lamport.tla.toolbox.doc/plugin.xml

org.lamport.tla.toolbox.feature.standalone/feature.xml

org.lamport.tla.toolbox.feature.uitest/.project

org.lamport.tla.toolbox.feature.uitest/build.properties

org.lamport.tla.toolbox.feature.uitest/feature.xml

org.lamport.tla.toolbox.feature.uitest/pom.xml

...louds/src/org/lamport/tla/toolbox/jcloud/Application.java

...rg/lamport/tla/toolbox/jcloud/CloudDistributedTLCJob.java

...rc/org/lamport/tla/toolbox/jcloud/CloudTLCJobFactory.java

...ort/tla/toolbox/jcloud/EC2CloudTLCInstanceParameters.java

...toolbox/jcloud/EC2PropertyCloudTLCInstanceParameters.java