readd CFLAGS that got lost in autotools conversion
fix a few small issues in the memory plugin

 * Missing function prototype.
 * Removed unused variable keyn.
 * Removed useless repetition of static buffer size in strncmp.
 * Error handling for bad meminfo file.
 * Return a value from a non-void function.
missing include and splint comments
also update the license crap
fix misuse of sizeof
cpu.c: remove deadstore, only compute extinfo once