qh and nerd patches

[robin.sonefors at op5.com]

So, a couple of more patches

The first two patches makes the query handler more discoverable, by adding a
help query handler that both lists all registered handlers, and strongly
suggests a common way for query handler authors to document their handlers.

The second two patches fixes two bugs in the nerd channels - one crash, one
pretty serious bug.


------------------------------------------------------------------------------
Monitor your physical, virtual and cloud infrastructure from a single
web console. Get in-depth insight into apps, servers, databases, vmware,
SAP, cloud infrastructure, etc. Download 30-day Free Trial.
Pricing starts from $795 for 25 servers or applications!
http://p.sf.net/sfu/zoho_dev2dev_nov