Main

Fix simple but nasty memory leak.

Reformat CMakeLists.txt, use gold linker, reformat several error
messages to remove extra double quotes, and confirm path is regular file
before adding to the input file list.

Additional minor output formatting fixes.

Fix minor formatting bug and improve error message handling.

Improve PCA post processing output message formatting.

Continued improvements to PCA; handle errors better, make number of
processing threads configurable, and reversed the "keep-orig" option to
"delete-orig" which makes more sense.

Converted PCA to be multithreaded and use libpackjpg instead of calling
the old packjpg executable. This works much better! Need to handle a few
error conditions and do some more testing with decompress.

Adding ProtectedAndSynchronizedQueue.

Remaking a few changes that seem to have been missed in the merge (?).

Updated packJPG to latest merged version. Also updated PCA CMake to build packJPG as an external project.