Use CMake to resolve most dependencies

The CEF dependency is not resolved using CMake because it's only
available behind a CAPTCHA, and the Boost dependency is not resolved
using CMake because it is a relatively large dependency that is better
shared between LOOT and its dependencies that use it, instead of each
having to build a separate copy.

This is slower than the existing Travis script, because all targets in
the dependencies are now built, but it is more portable.

scripts/install-step.travis.sh

@@ -1,37 +0,0 @@
-#!/bin/bash
-set -ev
-
-# Move out of LOOT repo path.
-cd ../..
-
-# Install libespm.
-wget https://github.com/WrinklyNinja/libespm/archive/2.5.0.tar.gz -O - | tar -xz
-mv libespm-2.5.0 libespm
-
-# Build yaml-cpp
-wget https://github.com/WrinklyNinja/yaml-cpp/archive/patched-for-loot.tar.gz -O - | tar -xz
-mv yaml-cpp-patched-for-loot yaml-cpp
-mkdir yaml-cpp/build && cd yaml-cpp/build
-cmake ..
-make yaml-cpp
-cd ../..
-
-# Build libgit2
-wget https://github.com/libgit2/libgit2/archive/v0.24.0.tar.gz -O - | tar -xz
-mv libgit2-0.24.0 libgit2
-mkdir libgit2/build && cd libgit2/build
-cmake .. -DBUILD_SHARED_LIBS=OFF
-make git2
-cd ../..
-
-# Build libloadorder
-wget https://github.com/WrinklyNinja/libloadorder/archive/7.0.0.tar.gz -O - | tar -xz
-mv libloadorder-7.0.0 libloadorder
-mkdir libloadorder/build && cd libloadorder/build
-cmake .. -DPROJECT_ARCH=64 -DPROJECT_STATIC_RUNTIME=OFF -DBUILD_SHARED_LIBS=OFF -DGTEST_ROOT=../gtest-1.7.0
-make loadorder64
-cd ../..
-
-# Install pseudosem
-wget https://github.com/WrinklyNinja/pseudosem/archive/1.0.1.tar.gz -O - | tar -xz
-mv pseudosem-1.0.1 pseudosem