ALL: Remove optimization unstable code on checking for null after new.

These issues were identified by the STACK tool.

By default, the C++ new operator will throw an exception on allocation
failure, rather than returning a null pointer.

The result is that testing the returned pointer for null is redundant
and _may_ be removed by the compiler. This is thus optimization
unstable and may result in incorrect behaviour at runtime.

However, we do not use exceptions as they are not supported by all
compilers and may be disabled.

To make this stable without removing the null check, you could qualify
the new operator call with std::nothrow to indicate that this should
return a null, rather than throwing an exception.

However, using (std::nothrow) was not desirable due to the Symbian
toolchain lacking a <new> header.
A global solution to this was also not easy by redefining "new" as "new
(std::nothrow)" due to custom constructors in NDS toolchain and various
common classes.

Also, this would then need explicit checks for OOM adding to all new
usages as per C malloc which is untidy.

For now to remove this optimisation unstable code is best as it is
likely to not be present anyway, and OOM will cause a system library
exception instead, even without exceptions enabled in the application
code.
Merge pull request #417 from digitall/STACK_fixes

ALL: Fix optimization unstable code on checking for null after new.