MOAI_WITH_EXT_COMPONENTS set up in Android build.

MOAI_WITH_EXT_COMPONENTS is now defined if MOAI_COMPONENTS is
defined/used in the Android build.

The include directory of MOAI_COMPONENTS is now also added to
MY_HEADER_SEARCH_PATHS in the Android build scripts.
Merge branch 'feature-moai_components_android' into nanocell-development
Added YAML support to the Android host.

Added libyaml and luayaml to the Android host and build scripts. The
build.sh and make_host.sh files now have an additional flag that
enables this, --use-yaml <true | false>.
Merge branch 'feature-luayaml_android_support' into nanocell-development