[vim] Make Y act more like D

Y is now essentially y$
[zsh] Fix Android SDK paths (again)

$ANDROID_SDK, not $ANDROID_SDK_HOME!
[vim] Use vim-pandoc-legacy

The github repository for the legacy version of vim-pandoc moved to
vim-pandoc-legacy. Unfortunately this breaks the git submodule.

Even though the legacy version is unsupported, I still need it, because
the new version requires vim 7.4, and Debian Wheezy is on vim 7.3.