Append instructions for MacOSX. Warn against Maven > 3.0
Append instructions for MacOSX. Warn against Maven > 3.0

elexis/elexis-3-core,elexis/elexis-3-core,sazgin/elexis-3-core,sazgin/elexis-3-core,sazgin/elexis-3-core,sazgin/elexis-3-core,elexis/elexis-3-core,elexis/elexis-3-core