Changing the <<Could not fetch content>> condition behaviour and more

Hello all !

I want to know if it is possible to change the message of a Could not
fetch content when accessing an http service from the gateway.

Reasons:
	I)  Im in Mexico !!! people here speaks spanish !
	II) Clients should not know that the gateway is having problems,
		system conditions, should not be reported to end user
		at any moment !

Instead:
	I)  A config (or temporary patch) should be applied to change 		the
Message, or to even avoid the message.
	II) All the pending requests should be passed to a pending tasks
		queue thread that would keep trying to retrieve the
		content until it gets it, and log or report to someone
		of the situation.

I'm not familiar at all with Kannel's code, and I would change it to
myself or If I have the time to create this new feature (II) I would
contribute it to the comunity, but I need someone to tell me which files
should be affected, and even better, the whole process of requesting a
post-url mapped to the code itself.

Thank you all !

== Oscar
OM MANI PEME HUM