2GB limit

• ddjvu: tiff generation improvements
• djvumake: security checks on INCL chunks
• all: updated for modern compilers
• win: moved to msvc2019
• osx: nfd filename normalization
• bugs: fixed several crashes on invalid inputs
• miniexp: fixed escape printout and macrochars
• djvudigital: can use poppler to find text
• csepdjvu: handle T comments for page titles
• bytestream: fixed 2GB limit
• gexception, gthread: cleanup obsolete code

large files

• simplified configuration scripts
• deadlock fixes
• miniexp under win32 uses tlsalloc instead of _thread vars (pb under xp)
• djvudigital can extract text and metadata using pdftotext.
• duplicate page titles are accepted
• bug fixes: overflow in bitmap/pixmap/iw44image sizes
• big fixes: handling INCL chunks in djvumake
• bug fixes: better support for large files (2gb)