remove gradle, switch to direct tycho build

build.gradle

org.eventb.texteditor.feature/feature.xml

org.eventb.texteditor.parent/pom.xml

org.eventb.texteditor.parsers/.classpath

org.eventb.texteditor.parsers/.project

...b.texteditor.parsers/.settings/org.eclipse.jdt.core.prefs

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

org.eventb.texteditor.parsers/build.gradle

org.eventb.texteditor.parsers/build.properties

org.eventb.texteditor.parsers/pom.xml

....parsers/src/org/eventb/texteditor/parsers/Activator.java

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

org.eventb.texteditor.ui/build.properties

....ui/src/org/eventb/texteditor/ui/outline/LabelHelper.java

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

org.eventb.texttools/build.gradle

org.eventb.texttools/build.properties

settings.gradle

tycho_build.gradle