Install `infocmp` for terminfo detection

- used in dotfiles to determine whether to fallback to an inferior TERM
Add a bunch of packages

- disk utilities
- remote filesystem utilities
- compression utilities
- multimedia viewers
- messaging (HipChat and `irssi`)
- graphicsmagick (faster)
Add missed `tk` dependency for `gitk`
Remove redundant `notify`
Improve custom synergy build

- `rm -rf` to prevent failure if prior dir not present
- `mv` instead of `cp` for atomicity (also works when files are in use)
- use absolute path for `creates=` (constantly rebuilding otherwise)
Add custom AUR packages

- AUR = Arch User Repository
- PostgreSQL UUID-OSSP extension isn't in main repos
- TODO: set up a proper custom repository
- this relies on these packages being on the Ansible host (Boo.)
Add `jq` = JSON Swiss Army knife

- amazingly useful for parsing/modifying/creating JSON
- unfortunately relies on Oniguruma (Regexp lib popularized by Ruby),
  which is only in AUR
Install Docker from source (and from this host)

- builds from source
- uses current host's Docker binary for bootstrapping
- installs a `systemd` unit file which sets permissions on the socket
Add LXPanel configuration
Install Dropbox with prereqs
Add systemd user services for lxpanel and dropbox