Added it into hasFeature() of all engines which returned `true` in
simpleSaveNames() before.
As mentioned in #788, SCI is not always using simple names, so it
doesn't have such feature now.
Engines with "simple" savenames would support "Run in background" in
save/load dialog and gradual save slots unlocking. Other engines
save/load feature would be locked until save sync is over.
Recently we started to use this as new semantics, although in the past
we used simly <engine>_H. Now these guard defines are consistent with
rest of the files which are used in the engines.
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.
