json-cpp Code

Fix gcc -Wall warnings (patch from Matt McCormick)

Fixed warning(error?) on #if testing value of _MSC_VER without checking that it was defined.

Added missing "include/json/assertions.h" header in amalgamate.py.

Made it possible to drop null placeholders from array output.

This can be used when it's clear that the consumer is able to deal with
this, as web browsers are. Thanks to Yatin Chawathe for the patch.

Added an exit() to JSON_FAIL_MESSAGE to fix "no return" errors.

Got rid of several unnecessary includes of <iostream>.

Including <iostream> causes the file to be polluted with a static
initializer for the __ioinit symbol. This can harm binary startup time.
For more info, see here:

http://neugierig.org/software/chromium/notes/2011/08/static-initializers.html

Made JSON_USE_EXCEPTION's value in config.h a default that can be overridden.

This allows users to override it with their compiler invocation. For example:

g++ -D JSON_USE_EXCEPTION=0 ...

Updated bug-fix list.

bug#2407932: strpbrk() could fail for NULL pointer.

bug#3306345: minor typo in Path::resolve() -- missing bang.