hw: off-by-one bug when determining the last IRQ

Fix #1169
hw: prevent from off-by-one bugs in PIC classes

Instead of using Pic::MAX_INTERRUPT_ID this commit introduces more
conveniently the Pic:NR_OF_IRQ.

Ref #1169
ahci: throw exception if device can not be found

Fixes #1183
hw: avoid locks before cache initialization

Fix #1190
run-tool: enable image loading via openocd

By adding: "--target jtag \
            --jtag-debugger <debugger configuration> \
            --jtag-board <board configuration>" to the RUN_OPTs
this commits enables the run-tool to load and execute an ELF image
via JTAG to the target platform.

Fixes #1191
vbox: rework irq injection code

Issue #1188
vbox: save/restore fpu state of EMT thread

Issue #1188
vbox: disable ioapic support by default

and add xml configuration option to switch it on if required. Avoids trouble
on Windows 7 guest where IRQ injected by VMMDev PCI device is not delivered.

If ioapic is required and Windows guest addition "hangs", look in file
DevPCI.cpp, function pciSetIrqInternal, variable fIsApicEnabled. If

config[0xde] == 0xbe
config[0xad] == 0xef

it works. "Deadbeaf" seems to/should be set in ACPI file vbox.dsl. Happens for
unknown reason not on Genode/Nova.

Fixes #1188
pthread: remove obsolete warning avoidance

Issue #1188