A lyrics and chords formatting program

Changes for 6.010 - 2023-06-05

• !ChordPro functionality
• Allow line continuation for input lines using a backslash.
• Allow define chord "|" in config.
• Allow graceful handling of rootless chords.
• Allow simple markup in chords. Yes, this includes grid chords.
• Add flags for preprocessor pattern replacements.
• Allow image scale as a percentage.
• Experimental: Absolute placement for images.
• Experimental: Diagram control in {define}.
• Remove diagrams.auto from config.
• !BugFixes
• Add Pod::Usage to required modules. Some distros seem to have removed it from the core.
• Add jpeg library to MacOS kit.
• Add some missing files for docs building.
• Fix root relocation when transcoding to a movable system.
• Fix missing parser in {define XX} without frets etc.
• Fix forum 1696 (chord recall with trans{code,pose}).
• Fix issue #269 (problem with page labels).
• Fix issue #270 (PDF outlines issues, 'letter' setting).
• Fix issue #273 (PDF CreationDate string is not conformant, but PDF::API2 2.042+ rejects conformant strings).