Add Taffybar and missing dependencies

This adds taffybar and all of its missing dependencies.

* hstringtemplate https://www.dropbox.com/sh/7dkiktec4zepnzu/1V61PncuuW/haskell-hstringtemplate
* executable-path https://www.dropbox.com/sh/7dkiktec4zepnzu/sMc7yK0Sks/haskell-executable-path
* io-storage https://www.dropbox.com/sh/7dkiktec4zepnzu/phbOJle9k8/haskell-io-storage
* dyre https://www.dropbox.com/sh/7dkiktec4zepnzu/gO08Imx_o5/haskell-dyre
* hashtables https://www.dropbox.com/sh/7dkiktec4zepnzu/Jlb3N6cRFb/haskell-hashtables
* gtk2hs-buildtools https://www.dropbox.com/sh/7dkiktec4zepnzu/wuf3fc08_d/gtk2hs-buildtools
* glib https://www.dropbox.com/sh/7dkiktec4zepnzu/xynLmPQFUR/haskell-glib 
* gio https://www.dropbox.com/sh/7dkiktec4zepnzu/j4g4WN4iDc/haskell-gio
* cairo https://www.dropbox.com/sh/7dkiktec4zepnzu/4WYn072Bt_/haskell-cairo
* pango https://www.dropbox.com/sh/7dkiktec4zepnzu/T4rkmm3CsZ/haskell-pango
* gtk https://www.dropbox.com/sh/7dkiktec4zepnzu/g8MTr6SCwe/haskell-gtk
* gtk-traymanager https://www.dropbox.com/sh/7dkiktec4zepnzu/yqC90Lg5d4/haskell-gtk-traymanager
* taffybar https://www.dropbox.com/sh/7dkiktec4zepnzu/FqUNHgJyXf/haskell-taffybar