new behavor about KMemoryInfo:
Check if memory info from current platform is supported or not (for ex, MacOSX is not support)
If not, -1 is returned from memory parser. In this case, digiKam will try to continue to allocate memory. An error message is printed to the console as debug statement.
If yes, we try to check memory info. If an error occur, 0 is returned, else 1.

This will solve multiple issues from bugzilla about non show large images in preview or editor, if memory allocation to store decompressed pixels data is more than 100Mb

CC