fix logic inversion; sched_yield() == 0 success
workaround gcc 4.7 atomic_thread_fence issue

workaround gcc 4.7 atomic_thread_fence(memory_order_release) issue
where compiler fence does not appear to be added on x86.  Ordered stores
on x86 do not require any physical memory barrier for release semantics,
but a compiler optimization fence should prevent reordering of assembly
emitted for stores.
explicit flags for 32-bit compile with ABI_BITS=32

(e.g. gmake ABI_BITS=32)
stronger compiler barrier for Sun Studio < 12.1
noinline, noreturn, malloc attributes for MSC
document __alignof__() portability
define PLASMA_FEATURE_POSIX on POSIX platforms

define PLASMA_FEATURE_POSIX on POSIX platforms
(intended for use when choosing to include headers such as unistd.h)
encapsulate POSIX header use in interface *.h

encapsulate POSIX header use in interface *.h
check defined PLASMA_FEATURE_POSIX before including <unistd.h> in header
C11 and C++11 std types incl stddef.h, stdalign.h

- use C11 and C++11 std headers where available
- portable standard types from stddef.h, stdalign.h
minor: simplify code, remove unnecessary includes
uint32_to_ascii_base10 - convert uint to ASCII str
trim header includes; elide <xmmintrin.h>
use PLASMA_ATTR_MM_HINT_* instead of _mm_hint_*
fix typo of intrinsic in xlC prefetch (__dcbtst())
__attribute_alias__()
__attribute_aligned__(), __builtin_constant_p()
Sun Studio 12 C, 12.2 C++ attribute support

Sun Studio 12 C, 12.2 C++ attribute support
doc and link updates
compatibility defs for C11/C++11 alignof, alignas

compatibility defs for C11/C++11 alignof, alignas, _Alignof, _Alignas
for compilations not targetting C11 or C++11 standard level
minor: use plasma_attr.h __attribute_alias__()
__attribute_deprecated__