ChannelMerger isInterleaved() can return true

Added a test to ChannelMerger.isInterleaved() - if canMerge() returned
false, ChannelMerger is effectively "disabled" so the isInterleaved()
call is passed to its delegate Reader.
openThumbBytes interleaves return bytes as needed

When merging channels for a resultant byte[], FormatTools.openThumbBytes
now interleaves the channel arrays if reader.isInterleaved() returns
true.

This should fix interleaved image thumbnails displaying incorrectly.
Merge pull request #396 from hinerm/Interleaved-Fixes

Interleaved fixes
merge develop -D org -I include -E conflict -E needs-fixes -E broken: PR 351 (Add SPW support to FakeReader)
merge develop -D org -I include -E conflict -E needs-fixes -E broken: PR 380 (Removing ndpi from readers list for fs demo)
merge develop -D org -I include -E conflict -E needs-fixes -E broken: PR 390 (Add slf4j-log4j dependency in the test-suite component (rebased onto develop))
merge develop -D org -I include -E conflict -E needs-fixes -E broken: PR 392 (Logging docfix (rebased onto develop))
merge develop -D org -I include -E conflict -E needs-fixes -E broken: PR 404 (Add external list of broken URLs to linkcheck_ignore (rebased onto develop))