[Wrapper-user] patch (4/4) -- pass signals across control channel

[Robey P. <ro...@da...>]

This is the last and largest patch.

We use signals on our servers to indicate certain control messages.   
For example, HUP is used to mean "reload your config files".  The  
latest version of wrapper supports catching HUP (partially) so we've  
had to modify this patch a lot, but the functionality is the same.  I  
think this patch may be useful to others too.

A new option for signal handling is created: "CONTROL".  If that's  
set as the handler for a signal, a message is sent across the control  
channel indicating the signal, and it arrives in java-land as a  
"controlEvent" with event = WrapperManager.WRAPPER_CTRL_HUP_EVENT (or  
whatever).

This way, the JNI code doesn't have to try to catch signals -- only  
the wrapper process catches them, and passes them on.  In addition,  
USR1 and USR2 signals are supported.

robey