LOG server that writes log messages onto a file system.

Using this component, log messages of different processes can be redirected
to files on a file-system service. The assignment of processes to files can
be expressed in the configuration as follows:

! <start name="fs_log">
!   <resource name="RAM" quantum="2M"/>
!   <provides><service name="LOG"/></provides>
!   <config>
!     <policy label="noux"    file="/noux.log" />
!     <policy label="noux ->" file="/noux_process.log" />
!   </config>
! </start>

In this example, all messages originating from the noux process are directed
to the file '/noux.log'. All messages originating from children of the noux
process end up in the file '/noux_process.log'.
