Add .gitignore

Signed-off-by: Marko Saukko <marko.saukko@jolla.com>

.gitignore

+*.o
+Makefile
+moc_*
+RPMS/
+documentation.list
+src/connmanvpnconnectionproxy.cpp
+src/connmanvpnconnectionproxy.h
+src/connmanvpnproxy.cpp
+src/connmanvpnproxy.h
+src/libsystemsettings.prl
+*.so*
+src/mceiface.cpp
+src/mceiface.h
+src/pkgconfig/
+src/plugin/libnemosystemsettings.so
+src/plugin/plugin.moc
+tests/tests.xml
+tests/ut_diskusage
+
+