Add CMake generated files to .gitignore.

.gitignore

@@ -328,3 +328,13 @@ ASALocalRun/
 
 # MFractors (Xamarin productivity tool) working folder 
 .mfractor/
+
+# CMake files.
+/CMakeCache.txt
+/CMakeFiles/
+/Makefile
+/cmake_install.cmake
+
+# Built targets.
+libsealpir.a
+