Use long options instead of short ones

It is a little hard to learn what the options mean.

doc/manual/src/quick-start.md

@@ -19,7 +19,7 @@ to subsequent chapters.
    channel:
 
    ```console
-   $ nix-env -qaP
+   $ nix-env --query --available --attr-path
    nixpkgs.docbook_xml_dtd_43                    docbook-xml-4.3
    nixpkgs.docbook_xml_dtd_45                    docbook-xml-4.5
    nixpkgs.firefox                               firefox-33.0.2
@@ -31,7 +31,7 @@ to subsequent chapters.
 1. Install some packages from the channel:
 
    ```console
-   $ nix-env -iA nixpkgs.hello
+   $ nix-env --install --attr nixpkgs.hello
    ```
 
    This should download pre-built packages; it should not build them
@@ -49,13 +49,13 @@ to subsequent chapters.
 1. Uninstall a package:
 
    ```console
-   $ nix-env -e hello
+   $ nix-env --uninstall hello
    ```
 
 1. You can also test a package without installing it:
 
    ```console
-   $ nix-shell -p hello
+   $ nix-shell --profile hello
    ```
 
    This builds or downloads GNU Hello and its dependencies, then drops
@@ -76,7 +76,7 @@ to subsequent chapters.
 
    ```console
    $ nix-channel --update nixpkgs
-   $ nix-env -u '*'
+   $ nix-env --upgrade '*'
    ```
 
    The latter command will upgrade each installed package for which
@@ -95,5 +95,5 @@ to subsequent chapters.
    them:
 
    ```console
-   $ nix-collect-garbage -d
+   $ nix-collect-garbage --delete-old
    ```