avoid hardcoded dll names

configure.in

@@ -5631,7 +5631,7 @@ if test "$with_system_expat" = "yes"; then
         [AC_MSG_ERROR(expat.h not found. install expat)], [])
     AC_CHECK_LIB([expat], [XML_ParserCreate], [:],
     [AC_MSG_RESULT(expat library not found or functional.)], [])
-    MINGW_EXTERNAL_DLLS="$MINGW_EXTERNAL_DLLS libexpat-1.dll"
+    libo_ADD_MINGW_EXTERNAL_DLLS([libexpat],[MINGW_EXTERNAL_DLLS])
 else
     AC_MSG_RESULT([internal])
     SYSTEM_EXPAT=NO
@@ -5823,7 +5823,7 @@ if test "$with_system_libxml" = "yes"; then
         AC_MSG_ERROR([xsltproc is required])
     fi
 
-    MINGW_EXTERNAL_DLLS="$MINGW_EXTERNAL_DLLS libxslt-1.dll"
+    libo_ADD_MINGW_EXTERNAL_DLLS([libxslt],[MINGW_EXTERNAL_DLLS])
 else
     AC_MSG_RESULT([internal])
     SYSTEM_LIBXSLT=NO
@@ -5873,7 +5873,7 @@ if test "$with_system_libxml" = "yes"; then
         AC_MSG_ERROR([xmllint is required])
     fi
 
-    MINGW_EXTERNAL_DLLS="$MINGW_EXTERNAL_DLLS zlib1.dll libxml2-2.dll"
+    libo_ADD_MINGW_EXTERNAL_DLLS([libxml2],[MINGW_EXTERNAL_DLLS])
 else
     AC_MSG_RESULT([internal])
     SYSTEM_LIBXML=NO
@@ -6674,7 +6674,7 @@ if test "$with_system_curl" = "yes"; then
         ;;
     esac
 
-    MINGW_EXTERNAL_DLLS="$MINGW_EXTERNAL_DLLS libintl-8.dll libidn-11.dll libnspr4.dll nssutil3.dll libplc4.dll libplds4.dll nss3.dll ssl3.dll libgpg-error-0.dll libgcrypt-11.dll libssh2-1.dll libcurl-4.dll"
+    libo_ADD_MINGW_EXTERNAL_DLLS([libcurl],[MINGW_EXTERNAL_DLLS])
 else
     AC_MSG_RESULT([internal])
     SYSTEM_CURL=NO
@@ -7572,7 +7572,7 @@ if test "$with_system_hunspell" = "yes"; then
         HUNSPELL_LIBS=-lhunspell
     fi
     AC_LANG_POP([C++])
-    MINGW_EXTERNAL_DLLS="$MINGW_EXTERNAL_DLLS libhunspell-1.3-0.dll"
+    libo_ADD_MINGW_EXTERNAL_DLLS([libhunspell],[MINGW_EXTERNAL_DLLS])
 else
     AC_MSG_RESULT([internal])
     SYSTEM_HUNSPELL=NO
@@ -9759,7 +9759,7 @@ if test "$with_system_cairo" = "yes"; then
             AC_LANG_POP([C])
         fi
     fi
-    MINGW_EXTERNAL_DLLS="$MINGW_EXTERNAL_DLLS libfontconfig-1.dll libfreetype-6.dll libpixman-1-0.dll libpng15-15.dll libcairo-2.dll"
+    libo_ADD_MINGW_EXTERNAL_DLLS([libcairo],[MINGW_EXTERNAL_DLLS])
 else
     AC_MSG_RESULT([no])