Update BOSS references for LOOT

Most of it is simply replacing "BOSS" with "LOOT" or BOSS URLs with LOOT ones, there are a couple of more prose-ish changes as well:

```diff
-<p>Unlike previous versions of BOSS, BOSS v3 caches the results of condition evaluations, so performance is not really an issue. A regular expression check will still take longer than a file check though, so use the former only when appropriate to do so.
+<p>Unlike BOSS, which LOOT is based on, LOOT caches the results of condition evaluations, so performance is not really an issue. A regular expression check will still take longer than a file check though, so use the former only when appropriate to do so.
```
```diff
-<blockquote class="warning">Version 3 is incompatible with earlier versions, which should be removed. Any existing user rules must be manually recreated in BOSS's user interface. Some plugins sorted correctly in v2 may be sorted incorrectly by v3 until their metadata has been recorded. Please <a href="#contrib">notify the team</a> if you observe any load order issues.</blockquote>
+<blockquote class="warning">LOOT is incompatible with BOSS, which should be removed. Any existing BOSS user rules must be manually recreated in LOOT's user interface. Some plugins sorted correctly in BOSS may be sorted incorrectly by LOOT until their metadata has been recorded. Please <a href="#contrib">notify the team</a> if you observe any load order issues.</blockquote>
```
```diff
-<p>General discussion and the submission of questions, suggestions and metadata takes place in BOSS's official threads for <a href="http://forums.bethsoft.com/topic/1434397-rel-boss-for-oblivion/">Oblivion</a>, <a href="http://forums.bethsoft.com/topic/1472899-relz-boss-for-skyrim/">Skyrim</a>, <a href="http://forums.bethsoft.com/topic/1282711-relz-boss-for-fo3-thread-4/">Fallout 3</a> and <a href="http://forums.bethsoft.com/topic/1313081-rel-boss-for-fallout-new-vegas/">Fallout: New Vegas</a>.
+<p>General discussion and the submission of questions, suggestions and metadata takes place in LOOT's official threads for <a href="http://forums.bethsoft.com/topic/1434397-rel-boss-for-oblivion/">Oblivion</a>, <a href="http://forums.bethsoft.com/topic/1472899-relz-boss-for-skyrim/">Skyrim</a>, <a href="http://forums.bethsoft.com/topic/1282711-relz-boss-for-fo3-thread-4/">Fallout 3</a> and <a href="http://forums.bethsoft.com/topic/1313081-rel-boss-for-fallout-new-vegas/">Fallout: New Vegas</a> (note that some of these threads might say they're for BOSS due to the legacy of the software - that's okay!).
```
(Note how I added a parenthetical comment at the end of this one. I wasn't sure about the wording, but it can always be changed later if deemed necessary - and removed altogether once all the threads are LOOTified.)

```diff
-    <li><a href="http://www.darkcreations.org">Dark Creations</a>: For hosting BOSS's Bugzilla bug tracker that was used by v2 to collect anonymous unrecognised plugin reports. Particular thanks to its administrators Andalaybay and Xae for offering to host the tracker and helping to work around Firefox and Bugzilla bugs encountered.
+    <li><a href="http://www.darkcreations.org">Dark Creations</a>: For hosting BOSS's Bugzilla bug tracker that was previously used by BOSS to collect anonymous unrecognised plugin reports. Particular thanks to its administrators Andalaybay and Xae for offering to host the tracker and helping to work around Firefox and Bugzilla bugs encountered.
```
```diff
-<p>Only the history of version 3 is given, as changes prior to version 3 are irrelevant due to the complete redesign that occurred. The masterlists are updated far too frequently for their changes to be concisely recorded here, but a full history of changes to them may be viewed by browsing the GitHub repositories.
+<p>Only the history of LOOT is given, as BOSS's version history is irrelevant due to the complete redesign that occurred. The masterlists are updated far too frequently for their changes to be concisely recorded here, but a full history of changes to them may be viewed by browsing the GitHub repositories.
```
```diff
-	<li>BOSS completely redesigned from scratch and almost completely rewritten. See <a href="#appendix-diff">Differences between BOSS v2 and v3</a> for an overview of the changes.
+	<li>LOOT is completely redesigned from scratch from BOSS v2 and almost completely rewritten. See <a href="#appendix-diff">Differences between BOSS and LOOT</a> for an overview of the changes.
```

This change also implies some changes in the LOOT program code, namely using `%LOCALAPPDATA%/LOOT` instead of `/BOSS` and translation files now being `loot.{p,m}o`.

Also note that the "Downloads" on the front page still references and links to BOSS v3. This should be removed once there's a version released of LOOT proper.