Merge branch 'release-0.19'
Merge branch 'develop'
Merge branch 'release-0.19'
Add PNM loader imported from kmiya's sixel
Enable pnm format loader in loader.c
Minor fix
Build with frompnm.c
Don't use stbi_load_from_file
Add functions detect pnm/sixel image format
Do not use stbi loader if image format is pnm/sixel
Minor fix
Issue #2 Fix segmentation faults caused when
libcurl integration is enabled
Update manpage of img2sixel
Merge branch 'fix-segfault-without-arguments' into develop
Fix a GDK error caused by loading image from stdin
with gdk-pixbuf
Fix segmentation errors when loading stdin with gdk-pixbuf
Merge branch 'fix-loading-from-stdin-with-gdk-pixbuf' into issue-2
Merge branch 'fix-segfault-without-arguments' into issue-2
Update minor version
Merge branch 'issue-2' into release-0.19