Merge branch 'master' into release-1.3
Merge branch 'develop' into release-1.3
Update version
Update ChangeLog
Add pipe mode feature(-D/--pipe-mode)
Use fseek instead of rewind, and check the availability of fseek
Use clearerr instead of fseek
Interpret an image expanded by png_set_palette_to_rgb as a 3-channel image
Merge branch 'hotfix-for-paletted-png' into feature-pipe-mode
Update document for --pipe-mode
Include sys/select.h to fix build on MinGW environment
Minor fix
Include sys/types.h to use fd_set
Various fixes for MinGW build
Merge branch 'develop' into feature-pipe-mode

Conflicts:
	converters/img2sixel.c
Update .travis.yml
Merge branch 'feature-pipe-mode' into develop

Conflicts:
	.travis.yml