Merge pull request #887 from imunro/dev_5_0

Implement pre-loading for .sdt files in the interest of performance.
merge dev_5_0 -D org -I include -E exclude: PR 889 (Logback conversion)
merge dev_5_0 -D org -I include -E exclude: PR 890 (CZI: make sure that SubBlocks are correctly initialized in openBytes)
merge dev_5_0 -D org -I include -E exclude: PR 892 (Update JPEGTurboServiceImpl.java (rebased onto dev_5_0))