Main

Replace boost::filesystem with std::filesystem. Replace
boost::program_options with CLI11. Rename ProtectedAndSynchronizedQueue
to ProtectedQueue. Fix error with JPEG_REGEX. Bump version to v0.5.0.

Update PCA CMakeLists.txt. Build libpackjpg as a dependent external
project.

Use computed library path for install.

Adding missing include.

Add link time optimization to compiler (linker) flags.

Fixing items suggested by clang-tidy.

Minor formatting changes for running status output.

Adding non-verbose mode with "running" status information and progress
bar. Also added terminate function in preparation of adding proper
SIGINT handling.

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.