/**
   @page pkgconfig

   @section pkgconfig_intro Introduction

   pkg-config (http://pkgconfig.freedesktop.org/wiki/) is a helper
   tool used when compiling applications and libraries. It helps you
   insert the correct compiler options on the command line based on
   installed software, instead of hard-coded values.

   @section pkgconfig_usage Usage

   Using pkg-config it is as simple as:
   @verbatim
   # compile:
   gcc -c -o main.o main.c `pkg-config --cflags PKGNAME`

   # link:
   gcc -o my_application main.o `pkg-config --libs PKGNAME`

   # compile + link in a single step:
   gcc -o my_application main.c `pkg-config --cflags --libs PKGNAME`
   @endverbatim

   Where @b PKGNAME is your module, such as eina, eet, evas, ecore,
   ecore-x, eio and so on.

   One can do some queries such as the module version, other variables:
   @verbatim
   pkg-config --modversion PKGNAME
   pkg-config --variable=prefix PKGNAME
   @endverbatim

   @section pkgconfig_troubleshooting Troubleshooting

   Make sure @c pkg-config command is in your @c $PATH, otherwise
   you'll end with:

   @verbatim
   pkg-config: command not found
   @endverbatim

   The @b PKGNAME it searched using pkg-config's build location,
   usually @c /usr/lib/pkgconfig. This can be overwritten with @c
   $PKG_CONFIG_LIBDIR (usually for cross compile) or extended with @c
   $PKG_CONFIG_PATH. If you installed EFL to @c /opt/efl, then use:

   @verbatim
   export PKG_CONFIG_PATH="$PKG_CONFIG_PATH:/opt/efl/lib/pkgconfig"
   pkg-config --cflags --libs PKGNAME
   @endverbatim

   Otherwise you'll end with:
   @verbatim
   Package PKGNAME was not found in the pkg-config search path.
   Perhaps you should add the directory containing `PKGNAME.pc'
   to the PKG_CONFIG_PATH environment variable
   No package 'PKGNAME' found
   @endverbatim

*/