are there ways for 'idle timeout'?

Hi!

In situations where client application is unstable there is very big
chance that it will enter transaction, acquire very restrictive locks and
then hang. This means: connection is not lost, but nothing happens and any
transaction in conflict with those locks will hang too.
statement_timeout can help to detect this situation, but not to solve,
when most of applications fail. Currently the only way I see to solve is
to kill locked postgres backend, or (more difficult) find hanging client
among hundreds of similar.
I work with web-application (Apache-mod_php-Postgres), where PHP hangs
every 100000 requests or so, which means from a day to some weeks between
whole system hangs.
I could set up a cron job which will kill every postgres backend "idle in
transaction" which was started more than 10 minutes ago, but I can have
accident problems with some long-running tasks.
The best solution I see is having an (per session)
idle_transaction_timeout or idle_connection_timeout setting.
But there is no such thing in postgres!
Scanning through list I've not found any workaround.
Looking into TODO I don't see any plans for it.
Is it too difficult implementing or I've missed something or are there
workarounds?

Hoping on your responce,
Konstantin Pelepelin