fixed a memory leak happening when rescheduling an expire job
don't mark the object as evicted if it was obtained reverting to a shared/global storage
don't start sending a response if we still don't know if the get()/offset() call went through

we need to send an error back in case it failed , instead of pretending it was an empty value
there is no point to be so verbose if we exhausted the available filedescriptors

lower layers will be complaining already so the case won't pass unnoticed
try to mitigate fildescriptor exhaustion by closing all the cached connections

before trying again to obtain a new fd
updated libiomux