Fixed as_simd<logical<T>> specialization not getting defined when using GCC native vectors for architectures other then ARM.
Minor other related refactoring and cleanup.
NEON: added uint and int extract implementations.
Minor refactoring and reorganization of shuffle implementations.
Minor other stylistic changes and cleanup.
Minor stylistic changes.
Fixed warnings when building for 64 bit targets.
Refactored the sign flipper constant generation (while searching for the cause of Clang 3.3 miscompilation).