ignore some test/ios Xcode project files.
remove the -fvisibility-inlines-hidden option, which causes a bunch
of warnings during linking.
update to iOS7 as default SDK and some other updates.
Add the text editor
Add a protection for creating the Minimizer and DistSampler  with the plugin manager in multithreads
(thanks for Andreas, see ROOT-5335)
Fix also the DistSampler