Add the new backend-specific tls source to the build.

Also prune the build spec for the examples. -Iexpat/lib will have to be
added again if we ever use expat in the example clients directly, but
for now it's unnecessary.

SConstruct

@@ -40,6 +40,7 @@ Sources = Split("""
   stanza.c
   jid.c
   sock.c
+  tls_gnutls.c
   hash.c
   sasl.c
   sha1.c
@@ -52,6 +53,7 @@ Headers = Split("""
   strophe.h
   common.h
   sock.h
+  tls.h
   hash.h
   sha1.h
   md5.h
@@ -89,7 +91,8 @@ stropheenv.Append(CPPPATH=['.', 'src', join('expat','lib')])
 strophe = stropheenv.Library('strophe', path("src", Sources))
 Default(strophe)
 
-exenv = stropheenv.Copy()
+exenv = env.Copy()
+exenv.Append(CPPPATH=['.'])
 exenv.Append(LIBS=["strophe", "expat"])
 exenv.Append(LIBPATH=["."])
 if exenv["PLATFORM"] == "win32":
@@ -130,10 +133,10 @@ def testcase_runner(target, source, env):
 
 testenv = env.Copy()
 testenv.Append(CPPPATH=['.', 'src', join('expat','lib')])
-testenv.Append(LIBS=['strophe', 'expat'])
+testenv.Append(LIBS=['strophe', 'expat', 'gnutls'])
 if testenv["PLATFORM"] == "win32":
   testenv.Append(LIBS=["winmm", "ws2_32"])
-testenv.Append(LIBPATH=['.'])
+testenv.Append(LIBPATH=['.', '/usr/local/lib'])
 
 import SCons.Node
 test_builder = Builder(action = testcase_runner,