It's sometime useful to create a stream aliasing a buffer on the stack, and
it's nice if we don't need some extra malloc for this.
Example use:
BYTE buffer[20];
wStream s;
Stream_StaticInit(&s, buffer, sizeof(buffer));
Stream_Write_UINT16(&s, 0xff01);
Stream_Free(&s, FALSE);
Change the return type of Stream_Ensure*Capacity from void to BOOL to be
able to detect realloc problems easily. Otherwise the only way to detect
this was to check if the capacity after the call was >= the required
size.
In case Stream_Ensure*Capacity fails the old memory is still available
and need to freed outside.
This commit also adds checks to most calls of Stream_Ensure*Capacity to
check if the call was successful.
