Configure: allow to be run from outside of the source directory.

Note that when run from outside of the source directory, this script
won't generate Makefiles, since there are too many cases to support.

Change-Id: I5db7bde4998134bb98ff027201f45209ff8a2896
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
Reviewed-on: https://nginx-review.googlesource.com/1010
Reviewed-by: Martin Maly <mmaly@google.com>

auto/lib/conf

diff --git a/auto/lib/conf b/auto/lib/conf
index e1e4475..0a0d3dc 100644
--- a/auto/lib/conf
+++ b/auto/lib/conf
@@ -4,7 +4,7 @@
 
 
 if [ $USE_PCRE = YES -o $PCRE != NONE ]; then
-    . auto/lib/pcre/conf
+    . $NGX_AUTO/lib/pcre/conf
 
 else
     if [ $USE_PCRE = DISABLED -a $HTTP_REWRITE = YES ]; then
@@ -22,20 +22,20 @@
 
 
 if [ $USE_OPENSSL = YES ]; then
-    . auto/lib/openssl/conf
+    . $NGX_AUTO/lib/openssl/conf
 fi
 
 if [ $USE_MD5 = YES ]; then
 
     if [ $USE_OPENSSL = YES ]; then
-        have=NGX_HAVE_OPENSSL_MD5_H . auto/have
-        have=NGX_OPENSSL_MD5 . auto/have
-        have=NGX_HAVE_MD5 . auto/have
+        have=NGX_HAVE_OPENSSL_MD5_H . $NGX_AUTO/have
+        have=NGX_OPENSSL_MD5 . $NGX_AUTO/have
+        have=NGX_HAVE_MD5 . $NGX_AUTO/have
         MD5=YES
         MD5_LIB=OpenSSL
 
     else
-        . auto/lib/md5/conf
+        . $NGX_AUTO/lib/md5/conf
     fi
 
 fi
@@ -43,41 +43,41 @@
 if [ $USE_SHA1 = YES ]; then
 
     if [ $USE_OPENSSL = YES ]; then
-        have=NGX_HAVE_OPENSSL_SHA1_H . auto/have
-        have=NGX_HAVE_SHA1 . auto/have
+        have=NGX_HAVE_OPENSSL_SHA1_H . $NGX_AUTO/have
+        have=NGX_HAVE_SHA1 . $NGX_AUTO/have
         SHA1=YES
         SHA1_LIB=OpenSSL
 
     else
-        . auto/lib/sha1/conf
+        . $NGX_AUTO/lib/sha1/conf
     fi
 
 fi
 
 if [ $USE_ZLIB = YES ]; then
-    . auto/lib/zlib/conf
+    . $NGX_AUTO/lib/zlib/conf
 fi
 
 if [ $USE_LIBXSLT = YES ]; then
-    . auto/lib/libxslt/conf
+    . $NGX_AUTO/lib/libxslt/conf
 fi
 
 if [ $USE_LIBGD = YES ]; then
-    . auto/lib/libgd/conf
+    . $NGX_AUTO/lib/libgd/conf
 fi
 
 if [ $USE_PERL = YES ]; then
-    . auto/lib/perl/conf
+    . $NGX_AUTO/lib/perl/conf
 fi
 
 if [ $HTTP_GEOIP = YES ]; then
-    . auto/lib/geoip/conf
+    . $NGX_AUTO/lib/geoip/conf
 fi
 
 if [ $NGX_GOOGLE_PERFTOOLS = YES ]; then
-    . auto/lib/google-perftools/conf
+    . $NGX_AUTO/lib/google-perftools/conf
 fi
 
 if [ $NGX_LIBATOMIC != NO ]; then
-    . auto/lib/libatomic/conf
+    . $NGX_AUTO/lib/libatomic/conf
 fi