zlib & sqlite3: pkgconfig support

native pkg-config support for zlib and sqlite to elimate the need
to pass flags to configure or make stages in formulae.

Closes Homebrew/homebrew#34765.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/aria2.rb

@@ -39,14 +39,8 @@ class Aria2 < Formula
       --without-libgcrypt
     ]
 
-    # system zlib and sqlite don't include .pc files
-    ENV["ZLIB_CFLAGS"] = "-I/usr/include"
-    ENV["ZLIB_LIBS"] = "-L/usr/lib -lz"
-    ENV["SQLITE3_CFLAGS"] = "-I/usr/include"
-    ENV["SQLITE3_LIBS"] = "-L/usr/lib -lsqlite3"
-
     system "./configure", *args
-    system "make install"
+    system "make", "install"
 
     bash_completion.install "doc/bash_completion/aria2c"
   end

Formula/mkvtoolnix.rb

@@ -73,9 +73,6 @@ class Mkvtoolnix < Formula
   def install
     ENV.cxx11
 
-    ENV["ZLIB_CFLAGS"] = "-I/usr/include"
-    ENV["ZLIB_LIBS"] = "-L/usr/lib -lz"
-
     boost = Formula["boost"]
     ogg = Formula["libogg"]
     vorbis = Formula["libvorbis"]

Formula/pdf2htmlex.rb

@@ -54,27 +54,14 @@ class Pdf2htmlex < Formula
       # Fix linker error; see: http://trac.macports.org/ticket/25012
       ENV.append "LDFLAGS", "-lintl"
 
-      # And fix the zlib hunting.
-      ENV.append "ZLIB_CFLAGS", "-I/usr/include"
-      ENV.append "ZLIB_LIBS", "-L/usr/lib -lz"
-
       # Reset ARCHFLAGS to match how we build
       ENV["ARCHFLAGS"] = "-arch #{MacOS.preferred_arch}"
 
       system "./autogen.sh"
       system "./configure", *args
 
-      # Fix hard-coded install locations that don't respect the target bindir
-      inreplace "Makefile", "/Applications", "$(prefix)"
-
       system "make"
       system "make", "install"
-
-      # Fix breaking zlib pkg-config file issue.
-      inreplace "#{prefix}/fontforge/lib/pkgconfig/libfontforge.pc", "zlib", " "
-
-      # Fix breaking zlib pkg-config file issue number 2.
-      inreplace "#{prefix}/fontforge/lib/pkgconfig/libfontforgeexe.pc", "zlib", " "
     end
 
     # Prepend the paths to always find this dep fontforge instead of another.

Formula/spdylay.rb

@@ -25,9 +25,6 @@ class Spdylay < Formula
     system "automake"
     system "autoconf"
 
-    ENV["ZLIB_CFLAGS"] = "-I/usr/include"
-    ENV["ZLIB_LIBS"] = "-L/usr/lib -lz"
-
     system "./configure", "--disable-dependency-tracking",
                           "--prefix=#{prefix}"
     system "make", "install"