replacing all ifndef with pargma once

All the kernel header files now use pargma once rather than the ifndef,
as the pre-processed C files do not change while header files
are protected with pargma once. This will also solve any naming issues
caused by ifndef.

Convert license tags to SPDX identifiers

This commit also converts our own copyright headers to directly use
SPDX, but leaves all other copyright header intact, only adding the
SPDX ident. As far as possible this commit also merges multiple
Data61 copyright statements/headers into one for consistency.

mcs: scheduling context donation over ipc

After this commit, threads blocked on an endpoint can recieve a
scheduling context from the thread that wakes the blocked thread.

Remove platform IPC buffer register.

This removes the assumption that each platform sotres the IPC buffer
address in a platform-specific register. The IPC buffer address is
instead stored in a thread-local variable in libsel4 which must be
initialised by the runtime.

style: consistently attach return type

Add attach-return-type to astyle

libsel4: fix licenses

- some were incorrectly marked GPL (libsel4 is BSD)
- update NICTA --> DATA61 etc
- fix tags D61 --> DATA61
- update year to 2017

libsel4: Optional public symbols for external interfaces

CONFIG_LIB_SEL4_PUBLIC_SYMBOLS=y will disable inlining for external
interfaces (except deprecated functions), thereby providing public
symbols for easy linkage with other languages.

libsel4: Generate libsel4 definitions from the current ARCH as well as the SEL4_ARCH

SELFOUR-279: rename Wait -> Recv, add wrappers for seL4_Poll and seL4_Wait for notification objects.

This commit deprecates seL4_ReplyWait, removes seL4_NBwait completely,
and changes the return type of seL4_Wait to void (seL4_Wait should be
used for notification objects, and seL4_Recv should be used where
seL4_Wait was used previously for endpoints).

trivial: move seL4_Notify to deprecated.h

Add seL4_NBWait: non blocking wait for notifications and endpoints.

trivial: fix typo in x86 definition of seL4_Signal

AEP -> Notification: deprecate old API syscalls, functions and constants that refer to AEP's and introduce new ones that refer to Notifications

Removed CONFIG_BENCHMARK config option. All checks for '#ifdef CONFIG_BENCHMARK' replaced with '#if CONFIG_MAX_NUM_TRACE_POINTS > 0'.

Added support for using multiple tracepoints at the same time.

Streamline libsel4 and remove its libc dependencies.

There are now separate libs for benchmark, assert, printf, putchar
start/stop:

libs/libsel4benchmark
libs/libsel4assert
libs/libsel4printf
libs/libsel4putchar
libs/libsel4startstop

The primary changes are introducing sel4/sel4.h and removing std* types
plus porting assert and IO code from the kernel to libsel4assert,
libsel4printf, libsel4putchar.

This means the code within libsel4 and the newlibs do not overload any
typical libc entities. Instead the libraries use types like
seL4_Uint32 ... instead of uint32_t. And printf is now seL4_Printf and
assert is seL4_Assert ....

Finally, the only file modified that effects kernel code is
kernel/tools/bitfield_gen.py. It needed to be modified as it generates
files for both kernel and user space. And for user space the generated code
(types_gen.h) needed to use the new types and asserts. The changes should
not change what is generated for the kernel and I did a comparison of
kernel_final.{c|s} before and after my change and the only differences
were time stamps.

Bug: #15 Streamline kernel/libsel4 and remove its libc dependencies

x86: Make x86 the name of the architecture instead of IA32

IA32 is 32bit version of the x86 architecture. Whilst only IA32
is supported, much of the code is generic x86. Using a generic
x86 architecture will aid in future 64bit support