CF point writing works for nc4 classic and structures. can read back in.
review IntelliJ analysis; update copyright
review IntelliJ analysis; update copyright;
add unsigned to attributes and ncml.
fix units tests
fix units tests;
refactor CFGridWriter -> CFGridWriter2
review IntelliJ analysis; update copyright;
fix unit tests
Merge branch '4.5.2' of https://github.com/Unidata/thredds into 4.5.2