JBIDE-13973: Adding -Dorg.eclipse.ui.testsDisableWorkbenchAutoSave=true

See https://bugs.eclipse.org/bugs/show_bug.cgi?id=405456
"Trunk" jobs now use TP 4.30.5.Alpha6-SNAPSHOT
JBIDE-13407 add new profiles: sign and signAndPack200
JBIDE-13407 add new profiles: sign and signAndPack200
JBIDE-14690: Tycho 0.18.0
add version to exec-maven-plugin plugin (JBIDE-14695, JBIDE-13407)
Reference TP release 4.30.5.Alpha6
s/4.30.5.Alpha6/4.30.5.Beta1-SNAPSHOT/g in prep for Beta3/CR1
s/Beta2/Beta3/g in prep for Beta3/CR1