Re-implementation of the loader service, ref #187

The original loader service was primarily motivated by the
browser-plugin scenario presented on our live CD. The new version
implements a more general session interface, which widens the
application scope of the service and, at the same time, reduces its
implementation complexity.

The complexity reduction is achieved by removing the original limitation
of supplying the new sub system as a single binary blob only. The server
used to implement heuristics and functionality for dealing with
different kinds of blobs such as ELF images or TAR archives. This has
been replaced by a session-local ROM service, which can be equipped with
an arbitrary number of ROM modules supplied by the loader client prior
starting the new sub system. Even though the TAR support has been
removed, a separate instance of the 'tar_rom' service can be used within
the subsystem to provide the formerly built-in functionality.
Implement RAM accounting
Adapt QPluginWidget to the new loader interface
Update zlib to version 1.2.7, fix #196
Use OO-means to copy capabilities (fix #182)

Whenever Native_capability or its derivation Capaility is memcpy'd no copy-
constructor/assignment-operator is used and thereby implementation of
reference-counting gets impossible for these objects. Use object-oriented
means like e.g. copy-constructor instead.
Add compiler helper function to supress type deduction bug.
Fiasco.OC: smart-pointer for kernel capabilities.

Implements Native_capability as smart-pointer type referencing Cap_index
objects. Whenever capabilities are copied, assigned, constructed, or destructed
the reference-counter of the Cap_index is incremented/decremented. When it
reaches zero the Cap_index is removed from the process-global cap_map and
gets freed. Fix for issue #32.
Delete Sliced_heap::Block object when freeing.

When a portion of the sliced heap gets freed, the corresponding block
gets removed from the list of blocks, and it's dataspace containing the
block gets detached, but it's destructor never gets called. This leads
to leaking capabilities, when Native_capability is implemented as
smart-pointer, because the destructor of Ram_dataspace_capability that
is part of the Block object gets never called.
Fiasco.OC: fix l4_task_cap_equal semantic.

The syscall l4_task_cap_equal almost returns false although the referenced
kernel-objects are equal. This patch changes the semantic of the syscall so
that whenever two capabilities refering the same kernel-object are compared
it will return true. Please refer to the discussion of the following mail
thread:
  http://www.mail-archive.com/l4-hackers@os.inf.tu-dresden.de/msg05162.html
Fiasco.OC: keep reference to capabilities in use.

Due to recently introduces smart-pointers to Cap_index objects it's
necessary to always keep at least one reference as long as a corresponding
slot in the capability-space of a process is in use. This is especially
important for L4Linux that uses cap-slots directly without the given
abstractions of Genode.
Fiasco.OC: check for leaks while thread creation

When unmarshalling capabilities it is checked, whether a capability with the
id was leaking, but this isn't done when creating a thread. Here the capability
is transfered indirectly via the thread state object. This patch checks for
old leakage capabilities while thread creation.
Qt4: fix Genode thread deletion

With this patch the Genode thread used by the QThread class gets deleted
when 'QThread::wait()' gets called and the timeout didn't trigger or when
'QThread::terminate()' gets called.

Fixes #193.
Fiasco.OC: increase core link address

This patch increases core's link address to 0x490000 to avoid region
overlaps with bootstrap on 64-bit Fiasco.OC.

Fixes #197.
Increase stack size of entry points

This patch increases the stack size of entrypoint threads in the PCI and
PS/2 drivers, in the Terminal server and in the Signal service for 64-bit
Genode/Fiasco.OC built with -O0.

Fixes #198.
Enable Noux for x86_64

Fixes #199.
Increase the JDB kernel object names buffer size

This patch increases the size of the JDB kernel object names buffer. The
original size was too small for some Genode scenarios and caused missing
thread names in the kernel debugger thread list.

Fixes #191.
Use placement new for Heap::Dataspace (fix #203)

This commit introduces placement new/delete, and a constructor for
Heap::Dataspace objects. It fixes the usage of uninitialized Dataspace
objects when expanding the heap that lead to problems in conjunction
with Native_capability smart-pointer in base-foc. Please refer to
issue #203.
Add std::terminate to ldso whitelist.

Due to recent changes on the Fiasco.OC platform, when building ldso
applications for this platform the std::terminate function is needed
by the ~Ipc_server destructor. So we've to add it to ldso's whitelist.
SDL audio support

This patch implements a Genode-specific audio backend for SDL.

The audio volume (in percent) can be configured in the config file of the
SDL application:

<config>
	<sdl_audio_volume value="100"/>
</config>

Fixes #204.
Set argv[argc] to 0 in 'config_args' libc plugin

Fixes #201.