.shell/aliases: document fstab line for makepkgtmp alias
.shell/aliases: add sdmesg for "sudo dmesg"
.gitconfig: allow creating .tar.xz archives
.shell/functions: add gitarc to ease the use of "git archive"
.shell/aliases: add xo alias for xdg-open
.shell/aliases: add gpg-keysrv alias for public gpg usage