Jfbview Versions Save

• Add support for password-protected PDF files (#50)
• Add inverted ("dark") and sepia color modes (#52)
• Fix garbled display when framebuffer device memory is horizontally padded (d239fb1)
• Fix weird line characters in Linux console in UTF-8 locales (e5b0669)
• Reduce binary size by making jpdfgrep and jpdfcat symlinks to jfbview (#38)
• Overhaul build system to CMake and fix MuPDF at specific version (#36)
• Set up automated DEB and RPM packaging via Travis CI for a variety of CPU & OS variants
• Add automated tests
• Other misc bug fixes (fe9e832, e60e64f, 6bf4593, #44, #47)

Fix compilation error with glibc 2.30 (issue #31)