superenv: look for pc files under prefix, not repository

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Fixes #14571; clisp superenv issue
Fixes #14542; ocaml superenv issues

This patch removes most of the settings for CC, CXX etc. because we are trying to be minimal. Then we force the compiler to Homebrew's choice underneath in superenv. We however leave LD because we prefer that build-systems use the c-compiler for linking, it generally works better (copiously tested), however when the build-system explicitly calls ld, we respect that. This gets around the ocaml bug in question, since somehow clang was crashing during link, but the ld tool itself (which is kind of clang, kind of llvm-gcc) is okay with this.

Also moved the setting of O (so that cc-args are refurbished) into a make wrapper. Not sure if this matter much, but seems more consistent.
libcouchbase 1.0.6

Closes #14581.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
Simplify `brew outdated` even further

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
String.f convenience function for brew irb

eg. "ack".f
samba 3.6.7
redis 2.4.17

Closes #14586.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
monetdb depends on pkg-config

Closes #14578.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
webp 0.2.0

Closes #14593.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
Hide --disable-debug from non verbose output also
More brew irb examples
Revert the user-PATH fix

User paths might have anything in them, anything can break builds.

Instead special case these two formula with the view to having an eventual DSL to allow injection of user paths into superenv. Certainly defaulting to off.
make -e has env-vars override Makefile vars

So the CC= in the Makefile is overridden by the $CC setting. I considered doing this generally, but as it stands we keep most of the user's environment in both superenv and stdenv so it's too risky. But I wanted to commit one example of it at least.
Consider superenv “servile” during configure

superenv defaults to servile mode. In servile mode:

* If 'gcc' is called, then 'gcc' is run (we ignore HOMEBREW_CC)
* CFLAGS (optimizations) are not applied
* ARGV is not mangled (TODO though we should apply fixes)
* -I and -L environment is still forcibly inserted.

This fixes, eg. jack which was still broken with stdenv. Jack was broken because we set CC in stdenv, and Jack has a stupid build-system. Unsetting CC allowed Jack to find and use the gcc tool it so demanded, but (previously) we would then substitute clang under its nose. The configure still failed. In servile mode (llvm-)gcc is used and Jack compiles.

In normal circumstances clang would then be inserted again during the make phase. But Jack uses the niche-wag build tool that we don't support for setting the O HOMEBREW_CCCFG flag that disables servile mode.
`brew --env` puts HOMEBREW_SDKROOT
MacOS.sdk_path is unlicensed Xcode aware

Now we should get an sdk_path, but tools like xcodebuild, xcode-select and xcrun will still error out. But at least more of Homebrew will work.

Also putting the Xcode 3 path finder last. We get bug reports because newer Xcodes are installed in parallel to older Xcodes. We want to find and use the newer Xcode's first. Xcode.prefix is pretty smart about that.

Refs #14558.
Doctor check for unlicensed Xcode

Checking the license text is probably the most future proofed method. Though for future reference other possible methods are listed in the below ticket.

Closes #14558.
Remove plain "-O"
Refs #14558. Try to find tools when xcrun fails.