1st chunk fixes bootstrap
2nd fixes db-4.8 support
3nd fixes respecting user LDFLAGS 

http://bugs.gentoo.org/286620
http://bugs.gentoo.org/310167

--- libetpan-0.57/configure.ac
+++ libetpan-0.57/configure.ac
@@ -104,8 +104,9 @@
 fi
 AM_CONDITIONAL(HAVE_MINGW32_SYSTEM, test "$have_w32_system" = yes)
 
-# Check the C compiler.
+# Check the C and CXX compiler.
 AC_PROG_CC
+AC_PROG_CXX
 
 # Compiler flags.
 AC_ARG_ENABLE(debug,   [  --enable-debug          setup flags (gcc) for debugging (default=no)],
@@ -382,7 +383,7 @@
   case "$DBVERS" in
     3)
     AC_MSG_RESULT([version 3.x or above])
-    for lib in db-4.7 db-4.6 db-4.5 db-4.4 db-4.3 db-4.2 db-4.1 db-4.0 db-4 db4 db-3.2 db-3 db3 db; do
+    for lib in db-4.8 db-4.7 db-4.6 db-4.5 db-4.4 db-4.3 db-4.2 db-4.1 db-4.0 db-4 db4 db-3.2 db-3 db3 db; do
       if test "x$DBLINKED" = "x0"; then
 dnl        AC_CHECK_LIB($lib, db_create, [DBLIB="-l$lib"; DBLINKED=1], [])
 dnl installations of libdb4 function names are defined in db.h
@@ -452,11 +453,11 @@
   for flag in "pthreads" "pthread"; do
     if test "x$checkpthread" = "xyes"; then
       AC_MSG_CHECKING([for pthread_create with -$flag])
-      OLDFLAGS="$LDFLAGS"
-      LDFLAGS="-$flag $LDFLAGS"
+      OLDLIBS="$LIBS"
+      LIBS="$LIBS -l$flag"
       AC_TRY_LINK([], [pthread_create();], 
                       [pthflag=yes; checkpthread=no], 
-                      [pthflag=no; LDFLAGS="$OLDCFLAGS"])
+                      [pthflag=no; LIBS="$OLDLIBS"])
       AC_MSG_RESULT($pthflag)
     fi
   done