Get native build working on Debian Linux

- now './autoconf && ./configure && make' will produce ./dna executable
 - added various missing libraries to configure.in
 - fixed nacl CFLAGS and LDFLAGS settings in configure.in
 - make git ignore autoconf and configure detritus

.gitignore

@@ -6,9 +6,13 @@
 *.o
 *.suo
 .*.sw?
-dna
+configure
+autom4te.cache
+Makefile
+config.log
+config.status
 nacl/nacl-20110221/build
 nacl/naclinc.txt
 nacl/nacllib.txt
 serval.c
-
+dna

configure.in

@@ -14,9 +14,13 @@ echo " but fortunately it only needs to happen once.)"
 cd nacl
 ./nacl-gcc-prep
 cd ..
-LDFLAGS="$LDFLAGS "`cat naclbuilddir.txt`"/libnacl.a"
+CFLAGS="$CFLAGS -Inacl/"`cat nacl/naclinc.txt`
+LDFLAGS="$LDFLAGS nacl/"`cat nacl/nacllib.txt`
 
+AC_CHECK_LIB(m,sqrtf,[LDFLAGS="$LDFLAGS -lm"])
 AC_CHECK_LIB(nsl,callrpc,[LDFLAGS="$LDFLAGS -lnsl"])
 AC_CHECK_LIB(socket,socket,[LDFLAGS="$LDFLAGS -lsocket"])
+AC_CHECK_LIB(dl,dlopen,[LDFLAGS="$LDFLAGS -ldl"])
+AC_CHECK_LIB(pthread,pthread_create,[LDFLAGS="$LDFLAGS -lpthread"])
 
 AC_OUTPUT(Makefile)