Add checks for memset() and strstr()
Add checks for memset() and strstr()

According to `autoscan`, these are used by some of the generated C code, and
should be checked for at configure time.

GNOME/folks,renatofilho/folks,renatofilho/folks2,GNOME/folks,pwithnall/folks,renatofilho/folks2,pwithnall/folks,renatofilho/folks2,renatofilho/folks,pwithnall/folks,renatofilho/folks,renatofilho/folks,GNOME/folks,renatofilho/folks2