Contribute/BiteSizedTasks

API conversion

• Look for uses of malloc, and convert them to either g_malloc, g_new (more rarely g_try_malloc or g_try_new if a lot of memory is being allocated). Likewise, convert calloc to either g_new0 or g_try_new0. Drop return value checks unless using g_try_new/g_try_new0.
• Add checks for NULL return value to uses of load_image_targphys, qemu_find_file.
• Add checks for negative return value to uses of get_image_size.
• Associate external libraries with the object files that actually use them