astro/gpsbabel: add GUI option, clean up dependencies

• Add GUI option (requires qt4-gui,qt4-xml,qt4-network and qt4-webkit at runtime).
• Remove autoconf/pcre/glib20/gettext dependencies (unused).
• USE_QT4=linguist_build -> USE_QT4=linguisttools_build (GUI option only).
• Use system zlib.
• Regenerate patch.

PR: 201680
Submitted by: s3erios@gmail.com
Approved by: dev2@heesakkers.info