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/applications/cache/PhabricatorCaches.php

@@ -11,8 +11,7 @@ final class PhabricatorCaches {
 
   /**
    * Highly specialized cache for performing setup checks. We use this cache
-   * to determine if we need to run expensive setup checks (e.g., verifying
-   * submodule versions, PATH, the presence of binaries, etc.) when the page
+   * to determine if we need to run expensive setup checks when the page
    * loads. Without it, we would need to run these checks every time.
    *
    * Normally, this cache is just APC. In the absence of APC, this cache