According to the C/C++ standards, calling `memcpy(NULL, NULL, 0)` is
undefined behaviour. Recent GCC versions may rely on this by optimizing
NULL pointer checks more aggressively, see [1].

This patch tries to avoid calling std::memcpy with zero elements.
As a side effect, explicitly return NULL when requesting an empty block
from MemoryPoolAllocator::Malloc.

This may be related to #301.

[1] https://gcc.gnu.org/gcc-4.9/porting_to.html

Remove deprecated FileStream

Try to fix a potential seg fault on some compiler

Merge the fix from https://github.com/miloyip/itoa-benchmark/issues/8

Fix several -Wfloat-equal related comments in #293

Conflicts:
	doc/diagram/simpledom.png

Add -Wfloat-equal and fix all derived warnings 

fixed 'Unknown CMake command "find_package_handle_standard_args"'

Added INCLUDE(FindPackageHandleStandardArgs) before using find_package_handle_standard_args().

Fix #289 negative zero roundtrip (double only)

Fix #288 double quote in unicode escape

Changing copyright holders, and details in license