Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Bundling explanation of X11 and libxslt is a bit odd and confusing, bundle libxml2 and libxslt instead extracted from X11 and /usr/lib requirements.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

`ENV.Og` clears all optimization flags and adds `-g -O0`.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

`brew-unpack` is inspired by the `unpack` command of Haskell's Cabal.
`brew unpack <formulae ...>` will fetch the source code archives of one or more
formula and extract them into subfolders of the current working directory. An
alternate root directory may be specified by invoking the `--destdir` flag.

This provides some nice advantages for inspecting source code compared to
`brew install -i -f <formula>`:

  - The extracted source code won't be deleted when the Ruby process
    terminates---which allows for long-term experimentation.

  - The user has control over which directory the code is extracted into.

  - No install process is initiated, so accidentally typing the equivalent of
    `exit 0` will not cause `brew` to mess with an existing installation.

  - Several formulae may be unpacked at once.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

CMake will pick up static libs in /usr/local.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

The git command now uses --git-dir instead of --work-tree.
Using --work-tree won't work if you are inside another Git repository.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

`brew fetch --deps` will also cache the dependencies of any listed formulae.

If a formula is given, it will be checked for missing deps.
The formula does not have to be installed first.

Without a formula list, still checks all installed brews.

-n means 'natural order' instead of alpha-order, and will show
the order in which the deps will be installed.