CamelIMAPXServer: use g_return_if_fail() family of functions instead of g_assert()
CamelIMAPXServer: use g_return_if_fail() family of functions instead of g_assert()

* changed the function param sanity checking from assertions
  to the g_return*_if_fail() family of functions, so we can
  stumble along instead of barfing in front of the user

matzipan/evolution-data-server,Distrotech/evolution-data-server,Distrotech/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,tintou/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,tintou/evolution-data-server