nixpkgs manual: fix white space and indentation

doc/builders/fetchers.xml

@@ -3,15 +3,12 @@
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xml:id="chap-pkgs-fetchers">
  <title>Fetchers</title>
-
  <para>
   When using Nix, you will frequently need to download source code and other files from the internet. Nixpkgs comes with a few helper functions that allow you to fetch fixed-output derivations in a structured way.
  </para>
-
  <para>
   The two fetcher primitives are <function>fetchurl</function> and <function>fetchzip</function>. Both of these have two required arguments, a URL and a hash. The hash is typically <literal>sha256</literal>, although many more hash algorithms are supported. Nixpkgs contributors are currently recommended to use <literal>sha256</literal>. This hash will be used by Nix to identify your source. A typical usage of fetchurl is provided below.
  </para>
-
 <programlisting><![CDATA[
 { stdenv, fetchurl }:
 
@@ -23,19 +20,15 @@ stdenv.mkDerivation {
   };
 }
 ]]></programlisting>
-
  <para>
   The main difference between <function>fetchurl</function> and <function>fetchzip</function> is in how they store the contents. <function>fetchurl</function> will store the unaltered contents of the URL within the Nix store. <function>fetchzip</function> on the other hand will decompress the archive for you, making files and directories directly accessible in the future. <function>fetchzip</function> can only be used with archives. Despite the name, <function>fetchzip</function> is not limited to .zip files and can also be used with any tarball.
  </para>
-
  <para>
   <function>fetchpatch</function> works very similarly to <function>fetchurl</function> with the same arguments expected. It expects patch files as a source and and performs normalization on them before computing the checksum. For example it will remove comments or other unstable parts that are sometimes added by version control systems and can change over time.
  </para>
-
  <para>
   Other fetcher functions allow you to add source code directly from a VCS such as subversion or git. These are mostly straightforward names based on the name of the command used with the VCS system. Because they give you a working repository, they act most like <function>fetchzip</function>.
  </para>
-
  <variablelist>
   <varlistentry>
    <term>
@@ -88,11 +81,9 @@ stdenv.mkDerivation {
    </listitem>
   </varlistentry>
  </variablelist>
-
  <para>
   A number of fetcher functions wrap part of <function>fetchurl</function> and <function>fetchzip</function>. They are mainly convenience functions intended for commonly used destinations of source code in Nixpkgs. These wrapper fetchers are listed below.
  </para>
-
  <variablelist>
   <varlistentry>
    <term>

doc/builders/special.xml

@@ -8,5 +8,3 @@
  <xi:include href="special/fhs-environments.xml" />
  <xi:include href="special/mkshell.xml" />
 </chapter>
-
-

doc/builders/trivial-builders.xml

@@ -3,11 +3,9 @@
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xml:id="chap-trivial-builders">
  <title>Trivial builders</title>
-
  <para>
   Nixpkgs provides a couple of functions that help with building derivations. The most important one, <function>stdenv.mkDerivation</function>, has already been documented above. The following functions wrap <function>stdenv.mkDerivation</function>, making it easier to use in certain cases.
  </para>
-
  <variablelist>
   <varlistentry>
    <term>

doc/using/overrides.xml

@@ -3,15 +3,12 @@
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xml:id="chap-overrides">
  <title>Overriding</title>
-
  <para>
   Sometimes one wants to override parts of <literal>nixpkgs</literal>, e.g. derivation attributes, the results of derivations.
  </para>
-
  <para>
   These functions are used to make changes to packages, returning only single packages. <link xlink:href="#chap-overlays">Overlays</link>, on the other hand, can be used to combine the overridden packages across the entire package set of Nixpkgs.
  </para>
-
  <section xml:id="sec-pkg-override">
   <title>&lt;pkg&gt;.override</title>
 
@@ -45,7 +42,6 @@ mypkg = pkgs.callPackage ./mypkg.nix {
    In the first example, <varname>pkgs.foo</varname> is the result of a function call with some default arguments, usually a derivation. Using <varname>pkgs.foo.override</varname> will call the same function with the given new arguments.
   </para>
  </section>
-
  <section xml:id="sec-pkg-overrideAttrs">
   <title>&lt;pkg&gt;.overrideAttrs</title>
 
@@ -76,7 +72,6 @@ helloWithDebug = pkgs.hello.overrideAttrs (oldAttrs: rec {
    </para>
   </note>
  </section>
-
  <section xml:id="sec-pkg-overrideDerivation">
   <title>&lt;pkg&gt;.overrideDerivation</title>
 
@@ -124,7 +119,6 @@ mySed = pkgs.gnused.overrideDerivation (oldAttrs: {
    </para>
   </note>
  </section>
-
  <section xml:id="sec-lib-makeOverridable">
   <title>lib.makeOverridable</title>