Add documentation on gettext integration

	<li><a href="#manual-tutorial">Manual Makefile : tutorial</a></li>

      </ul>

      </li>

      <li><a href="#gettext-integration">Gettext integration and

      interaction with packages</a></li>

    </ul>

    <h3><a name="package-directory"></a>Package directory</h3>

    line <a href="#ex2line40">40</a>, which is used by Buildroot to download,

    compile, and then install this package. </p>

    <h3><a name="gettext-integration"></a>Gettext integration and

    interaction with packages</h3>

    <p>Many packages that support internationalization use the gettext

    library. Dependency on this library are fairly complicated and

    therefore deserves a few explanations.</p>

    <p>The <i>uClibc</i> C library doesn't implement gettext

    functionality, therefore with this C library, a separate gettext

    must be compiled. On the other hand, the <i>glibc</i> C library

    does integrate its own gettext, and in this case, the separate

    gettext library should not be compiled, because it creates various

    kind of build failures.</p>

    <p>Additionnaly, some packages (such as libglib2) do require

    gettext unconditionnally, while other packages (those who

    support <code>--disable-nls</code> in general) only require

    gettext when locale support is enabled.</p>

    <p>Therefore, Buildroot defines two configuration options:</p>

    <ul>

      <li><code>BR2_NEEDS_GETTEXT</code>, which is true as soon as the

      toolchain doesn't provide its own gettext implementation</li>

      <li><code>BR2_NEEDS_GETTEXT_IF_LOCALE</code>, which is true if

      the toolchain doesn't provide its own gettext implementation and

      if locale support is enabled</li>

    </ul>

    <p>Therefore, packages that unconditionnally need gettext should:</p>

    <ol>

      <li>Use <code>select BR2_PACKAGE_GNUTTEXT if

      BR2_NEEDS_GETTEXT</code> and possibly <code>select

      BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT</code> if libintl is

      also needed</li>

      <li>Use <code>$(if $(BR2_NEEDS_GETTEXT),gettext)</code> in the

      package <code>DEPENDENCIES</code> variable</li>

    </ol>

    <p>Packages that need gettext only when locale support is enabled

    should:</p>

    <ol>

      <li>Use <code>select BR2_PACKAGE_GNUTTEXT if

      BR2_NEEDS_GETTEXT_IF_LOCALE</code> and possibly <code>select

      BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT_IF_LOCALE</code> if

      libintl is also needed</li>

      <li>Use <code>$(if

      $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext)</code> in the

      package <code>DEPENDENCIES</code> variable</li>

    </ol>

    <h3>Conclusion</h3>