Fix Issue#17:  Added topicAttrName parameter, added compile time checks,
made topic parameter optional
Issue #13: Added topicOutAttrName as parameter to specify what attribute
to send topic to.  Will only search for this attribute from the data
stream, and not on the error stream.  We need to revisit search order.
Merge branch 'master' of github.com:IBMStreams/streamsx.messaging

Added mqtt operators to the compile

Conflicts:
	com.ibm.streamsx.messaging/toolkit.xml