JBIDE-15494 : apply Mylyn's fix to our forked Discovery strategy

Signed-off-by: Fred Bricon <fbricon@gmail.com>
bump plugins/features in jbosstools-central/examples to 1.5.2 since 1.5.1 will be released in JBT 4.1.0.1 / JBDS 7.0.1 (JBIDE-15510)