New formula: zsync 0.6.1
Fix xz building on x86-64

The assembly for the CRC checks fails to build for x86-64. Disable the assembly.
Use full path to du

Fixes #354
Shell.fm depends_on pkg-config

Fixes #399
Updates broken LFTP formula
ctags aka ctags-exuberant
Check GitHub for issues relating to build failures

Uses the GitHub issue search API, so it's very neat and concise. However you can get false positives, so it's not 100% useful. Still I think it is more useful than before, which was, nothing.

A further issue is it depends on the ticket at GitHub using the formula's proper name. So we should ensure this as we can.

Finally, it does add a possibly large delay to clean exit after a build error. We may want to fiddle with timeouts if it becomes troublesome.
Detect X11 when ENV.x11 is requested; dump in --config.
Escape spaces for archs_for_command

Use inject for concision.

Rename to archs from arch as it returns an array.
Add Makefile var and multi-replace support inreplace.
Update dtach to use new inreplace.
Update tmux to use new inreplace features.
Use new inreplace syntax where useful
LICENCE is a common spelling too
Formulary comments
Fixes #433
aka dbus
Update pngcrush to 1.7.7
Don't show non-64 bit caveats on non-64 bit systems

Also don't use HOMEBREW_PREFIX/bin, assume we're in the PATH, as it's most likely true, and if not, the guy has other problems or knows what he is doing.
Use full paths to strip, mktemp, cat and ls