Removed BAPI in favour of LOOT's API.

This currently breaks the BOSS application launcher, as that uses Bash's
global BOSS path `dirs['boss']`, which has been removed.
Fixed BOSS launcher.

Part of ongoing work for #106. However, Windows throws an error when
libloadorder is used to set the load order, so I can't test that I've
made the BAPI -> LOOT API swap correctly yet.
Updated libloadorder DLL.

Now at v4.0.1
(WrinklyNinja/libloadorder@8608eb1273d18849c980fff7d63db655659e9b5e).
Removed mentions of MSVC 2013 redist.

From general readme and installer. Also swapped BOSS API -> LOOT API in
general readme.
Updated repository readme.

Removed unnecessary HTML and added a link to the MSVC 2005 redist for
Windows XP users.
Merge pull request #112 from wrye-bash/wrinklyninja-loot-api

Replaced BOSS API with LOOT API. Also updated libloadorder, removed MSVC 2013 redist dependency, and updated the repository and general readmes. I've tested this out on a Windows XP virtual machine, and on Windows 8.1, and couldn't detect any issues.