Bump version number to 3.5.2

org.eventb.texteditor.feature/feature.xml

org.eventb.texteditor.feature/pom.xml

org.eventb.texteditor.parent/pom.xml

org.eventb.texteditor.parsers/META-INF/MANIFEST.MF

org.eventb.texteditor.parsers/pom.xml

org.eventb.texteditor.repository/category.xml

org.eventb.texteditor.repository/pom.xml

org.eventb.texteditor.ui/META-INF/MANIFEST.MF

org.eventb.texteditor.ui/pom.xml

org.eventb.texttools/META-INF/MANIFEST.MF

org.eventb.texttools/pom.xml