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

* Unshare code between ENV.llvm and ENV.setup_build_environment

Fixes Homebrew/homebrew#659

The TeX-live 2008 formula was out of date (there's a 2009), buggy,
and doesn't build 64-bit.

The MacTeX package works and is supported, with a 2010 version in the works.
Let's recommend that instead.

Fixes Homebrew/homebrew#1087

If a package contains a folder that has the same name as one of our
expected meta files, skip trying to install that folder.

(Otherwise we install an empty folder and can get odd permission errors
when trying to summarize after install.)

The code to try to move man into share didn't seem to be working, since
the code that warns if a top-level man was found was firing off.

Removing this apparently dead code.

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

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

Rationale: if you want complete control then you will most likely not like the `sudo chown -R` step as it's nuts.

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

Different llvm binaries were used to check build numbers and to compile with.
Normalize this, and normalize the variable name used to hold the xcode location.
(Calling it "prefix" is confusing, since there are already concepts in Homebrew
called "prefx".)

Replaced ENV.gcc_4_2 + comments with calls to "fails_with_llvm",
to specifically message to the user when a formula is known or suspected
to not build with LLVM. If the user specifies "--use-llvm", the message
will be displayed, but compilation will be tried anyway.

Since using LLVM is now an advanced/hidden feature instead of the
default on 10.6, we'll let the user try anyway (and submit patches
if things are now working.)

Reinstalls out outdated brews.
See: http://github.com/mxcl/homebrew/issues/issue/1324

This external command allows you to switch between installed versions of
a formula. If you have multiple versions of a formula in your cellar, the
standard "brew link" command will refuse to run.

This new command "brew switch" tries to unlink all versions of the brew
from the prefix, then links the specific requested version.

External command "brew fetch" now allows -f|--force to remove an
existing cached file before downloading.

When an "install -d formula" fails, and the user gets dropped into an
interactive shell, set the HOMEBREW_DEBUG_INSTALL env var to the name
for the formula that failed. Also set variable if the user requests an
interactive install in the first place.

Note that this may be different than the formula being installed, since
it may have been a dep that failed.

Also remove todo in utils; users can now look for HOMEBREW_DEBUG_INSTALL
in their prompt command, and adjust their prompts accordingly.

Plus more reassuring preamble.

Includes: generator script, ronn source, manpage output

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

Man page updates.

* Generator command is now an external command with additional options
* Added more brew commands
* Tweaks and reformats

If the user has, for instance, a non-system "xml2-config" in the path
ahead of the system and Homebrew folders, ./configure scripts which
look for and use this config script will get confused.

This command looks for Cocoa Applications (.app bundles) in the prefix
of all installed formulae. If any are found, they are linked into
"~/Applications", the system-defined location for per-user apps.

A formula using svn can now provide a spec:
    :revisions => {...revision numbers...}
that contains a mapping of revision numbers to use
for externals.

The name of the external is keyed to the revision to
use for that external.

The symbol :trunk should be used to specify the reivsion
of the main repo.

An example from the Ffmpeg formula:
    head 'svn://svn.ffmpeg.org/ffmpeg/trunk

',
        :revisions => { :trunk => 22916, 'libswscale' => 31045 }

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

Now makes use of `svn up` to make cache act like
a cache. Externals without a revision specified
are now checked out at HEAD, whereas before they
were ignored. Escaping arguments to backticks.
Making sure main repo is checked out before the
externals.

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

See:

* http://github.com/mxcl/homebrew/issues/issue/1359
* http://github.com/mxcl/homebrew/issues/issue/1438

Homebrew will now look for external commands that are +x on PATH, named
as "brew-<cmd>" or "brew-<cmd>.rb"

* Shell scripts are exec'd with some HOMEBREW variables set in the ENV.
* Ruby scripts are require'd directly.

See: http://wiki.github.com/mxcl/homebrew/external-commands