svn merge -r 79455:79892...

svn merge -r 79455:79892 svn+ssh://svn.lindenlab.com/svn/linden/branches/Branch_1-19-0-Server --> release

* DEV-10498 The agentN-ds host name was constructed incorrectly and caused services_base_url to be incorrect
* Fixed a potential crash bug caused by LSL library functions returning null pointers instead of empty strings.