Rename project in CMake

TODO: to create symlinks to the old names!
diff --git a/programs/ssl/CMakeLists.txt b/programs/ssl/CMakeLists.txt
index e0cfba0..9ba9241 100644
--- a/programs/ssl/CMakeLists.txt
+++ b/programs/ssl/CMakeLists.txt
@@ -2,7 +2,7 @@
 find_package(Threads)
 
 set(libs
-     polarssl
+     mbedtls
 )
 
 set(targets