Small bug fix

I changed the source so that passing nil to the dictionary argument results in sending an empty dictionary. Otherwise, libobjcipc crashes the process.

I also changed the IPCLog macro to only work when DEBUG is set in the makefile. Otherwise, libobjcipc spams the device console with tons of messages. There's no use for that unless you're debugging it, in which case you'll have the source to enable them yourself.

Please consider merging my fixes.