Use direct inclusion, not submodules, to bring Javelin into Phabricator

Summary:
Submoduling is slightly convenient for developers but hellishly difficult for many users. Since we make about a dozen updates to Javelin per year, just include the source directly.

Even if we run `git submodule status` more often, this creates additional problems for users with PATH misconfigured.

Fixes T2062 by nuking it from orbit.

Test Plan: Loaded site, browsed around. Grepped for references to submodules.

Reviewers: btrahan, vrana

CC: aran

Maniphest Tasks: T2062

Differential Revision: https://secure.phabricator.com/D4581

src/docs/installation_guide.diviner

@@ -63,8 +63,6 @@ dependencies:
   somewhere/ $ git clone git://github.com/facebook/libphutil.git
   somewhere/ $ git clone git://github.com/facebook/arcanist.git
   somewhere/ $ git clone git://github.com/facebook/phabricator.git
-  somewhere/ $ cd phabricator
-  somewhere/phabricator/ $ git submodule update --init
 
 = Installing APC (Optional) =
 
@@ -124,8 +122,7 @@ Since Phabricator is under active development, you should update frequently. To
 update Phabricator:
 
   - Stop the webserver.
-  - Run `git pull && git submodule update --init` in `libphutil/`,
-    `arcanist/` and `phabricator/`.
+  - Run `git pull` in `libphutil/`, `arcanist/` and `phabricator/`.
   - Run `phabricator/bin/storage upgrade`.
   - Restart the webserver.