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.
• Associate external libraries with the object files that actually use them
• For all "QEMUTimer*" variables that are initialized with timer_new, change them to "QEMUTimer" and initialize them with timer_init. Drop any timer_free calls (there aren't many, so this patch would fix small memory leaks too). (not quite bite-sized).

Error checking

• 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.

Dead code removal

• hw/display contains files named *_template.h. These are included many times with different values of the DEPTH macro. However, only the DEPTH == 32 case is used. Remove support for DEPTH != 32 in the template headers and in the file that include them.
• Look for functions that are named *_exit or *_exitfn in hw/ and that return int. They should all return zero. Make them return void, and remove the checks for the callers.
• Once the above change is done, remove the "Error **" argument from functions named *_unrealize in hw/

Tracing

• Add tracepoints. All functions that are named something_helper, and all functions mentioned in MemoryRegionOps are good candidates.