always search for libicu
read from stdin if no domain argument
added libicu48 to .travis.yml
print info of travis ci build environment
fix search for older libicu versions without pkg-config support
added mlocate to .travis.yml
removed mlocate / updatedb from .travis.yml
use libicu for UTF-8 lowercase conversion
fixed autoreconf warnings
added psl_str_to_utf8lower()
free allocated variable
updated docs, removed printing to stderr
fixed locale/charset support
added lowercase conversion to ASCII strings
respect test data being always UTF-8
fixed psl_str_to_utf8lower prototype
fixed compile issue with older libicu versions
don't fail configure run if libicu not detected
removed IDNA case test if libicu is not configured
some libicu cleanups