v2.2.7: Bug fixes, improvements and new features

Changes since v2.1.6:

• lib/zypper: Complete query/removal options (Thanks to Janne Heß);
• lib/cave: Fix an issue with -R option;
• New option --noconfirm to help non-interactive scripts (Cf. #43).
  Currently available for pkgng, yum, dpkg and zypper.

For developers:

• lib/{00_core,zz_main}: Refactor to support future option translation;
• Refactor code supports -w (download only) and -v (debug) options;
• Improve coding quality thanks to shellcheck;
• Move compile.sh to bin/compile.sh;
• Use lib/00_core#_translate_all to add future option translation;
• bin/check: Add script to inspect coding style issues (Cf. #54).