Features:

• implement --short-errors

Bug fixes:

• only consider a single package at a time with --print-requires, --print-requires-private, --print-provides, --modversion, --print-variable and --print-variables
• rewrite handling of --modversion, --print-variables and --variable to not require the dependency resolver

Enhancements:

• synchronized latest freedesktop.org changes to pkg.m4
• improve error reporting with legacy --atleast-version and similar flags