Add 'update_hash' and 'list' to tool/ports

Issue #1082
Enable hash checks for ports mechanism
rtc: document current interface

Issue #1148
vfs: catch lookup-failed exception on node discovery
nova: re-throw uncatched exception of dying thread

If the re-throw works, we will can see which exception type was thrown.
vmm utils: cpu-session parameter for VMM thread

Issue #1157
vbox: update to 4.2.24
vbox: enable guest additions

Fixes #1157
hw: fix section insertion in translation tables

Fixes an alignment problem introduced by commit "hw: map core on demand"
where physical address alignment wasn't checked anymore, when inserting
a section within the first-level table of ARM's short translation table
format.

Many thanks to Christian Prochaska for helping to debug the problem.
vbox: fix share-folder setup
doc: update porting guide to new port mechanism
Release notes for version 14.05
version: 14.05