Mac/Linux: Continue building but do not package dylib/so libraries.

End of an experiement in packaging both types of libraries.  It
mostly adds work without material gain.  We'll continue to build
both to test for breakage.  Additional comments on Linux build
environment at Linden and better SDK selection on Mac.

README.Linden

@@ -81,21 +81,25 @@
 
     Mac OS X:
     * lib/debug/libz.a
+    * lib/release/libz.a
+
+    Mac OS X (built but not in manifest):
     * lib/debug/libz.1.2.8.dylib (dylib - install path:
       @executable_path/../Resources/libz.1.dylib)
     * lib/debug/libz.1.dylib (symlink - link target)
     * lib/debug/libz.dylib (symlink)
-    * lib/release/libz.a
     * lib/release/libz.1.2.8.dylib
     * lib/release/libz.1.dylib
     * lib/release/libz.dylib
 
     Linux:
     * lib/release/libz.a
+    * lib/debug/libz.a
+
+    Linux (built but not in manifest):
     * lib/release/libz.so.1 (symlink)
     * lib/release/libz.so (synlink) 
     * lib/release/libz.so.1.2.8 (shared)
-    * lib/debug/libz.a
     * lib/debug/libz.so.1
     * lib/debug/libz.so
     * lib/debug/libz.so.1.2.8

autobuild.xml

@@ -59,9 +59,7 @@
           <key>manifest</key>
           <array>
             <string>lib/debug/libz.a</string>
-            <string>lib/debug/libz*.dylib</string>
             <string>lib/release/libz.a</string>
-            <string>lib/release/libz*.dylib</string>
           </array>
           <key>name</key>
           <string>darwin</string>
@@ -84,9 +82,7 @@
           <key>manifest</key>
           <array>
             <string>lib/release/libz.a</string>
-            <string>lib/release/libz.so*</string>
             <string>lib/debug/libz.a</string>
-            <string>lib/debug/libz.so*</string>
           </array>
           <key>name</key>
           <string>linux</string>

build-cmd.sh

@@ -59,7 +59,15 @@ pushd "$ZLIB_SOURCE_DIR"
         ;;
 
         "darwin")
-            opts="${TARGET_OPTS:--arch i386 -iwithsysroot /Developer/SDKs/MacOSX10.7.sdk -mmacosx-version-min=10.6}"
+            # Select SDK with full path.  This shouldn't have much effect on this
+            # build but adding to establish a consistent pattern.
+            #
+            # sdk=/Developer/SDKs/MacOSX10.6.sdk/
+            # sdk=/Developer/SDKs/MacOSX10.7.sdk/
+            # sdk=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.6.sdk/
+            sdk=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk/
+
+            opts="${TARGET_OPTS:--arch i386 -iwithsysroot $sdk -mmacosx-version-min=10.6}"
             # Install name for dylibs based on major version number
             install_name="@executable_path/../Resources/libz.1.dylib"
 
@@ -103,6 +111,21 @@ pushd "$ZLIB_SOURCE_DIR"
         ;;            
             
         "linux")
+            # Linux build environment at Linden comes pre-polluted with stuff that can
+            # seriously damage 3rd-party builds.  Environmental garbage you can expect
+            # includes:
+            #
+            #    DISTCC_POTENTIAL_HOSTS     arch           root        CXXFLAGS
+            #    DISTCC_LOCATION            top            branch      CC
+            #    DISTCC_HOSTS               build_name     suffix      CXX
+            #    LSDISTCC_ARGS              repo           prefix      CFLAGS
+            #    cxx_version                AUTOBUILD      SIGN        CPPFLAGS
+            #
+            # So, clear out bits that shouldn't affect our configure-directed build
+            # but which do nonetheless.
+            #
+            # unset DISTCC_HOSTS CC CXX CFLAGS CPPFLAGS CXXFLAGS
+
             # Prefer gcc-4.6 if available.
             if [[ -x /usr/bin/gcc-4.6 && -x /usr/bin/g++-4.6 ]]; then
                 export CC=/usr/bin/gcc-4.6