Version 0.6.1

Bug fixes

• Sets accurate CMake project version
• Allows compatibility with SameMajorVersion for downstream CMake projects
• Guard against including HDF5 directories if HDF5 is not enabled
• Include <iostream> where it's used
• Improve warnings for previous cabanacore and Cajita targets and simplify new Core and Grid targets
• Fix for heFFTe integer overflow with large system sizes
• Fix use of deprecated code in Cajita deprecation wrappers