Bump version to 1.11.0

Support for APT authentication. Closes #234 (#235)

Bump version to 1.9.12

Fix when $_APTMGR is full path. Closes #188

Update README.md

 * Linux Mint apt not supported because it's a custom shell script there.

Add missing tag to zsh completion

Fix DLDIR default directory. Closes #162

 * Set /var/cache/apt/apt-fast as default directory over
   /var/cache/apt/archives/apt-fast .

   Prevents apt warning:

    W: Problem unlinking the file apt-fast - pkgAcquire::Clean (21: Is a directory)

 * Update README and fix language in config file.

Add GPL v3 licence. Closes #160

Support metalink redirection as default.

 * Uses solution from #114. Drop section in FAQs.
 * Update manpage.
 * Update copyright years.

Fix return value for clean command