Frequency measurement with Arduino 1.5

I am trying to measure the resonant frequency of a tank circuit (capacitor and inductor in series) using an op-amp and the FreqCount library, available at

Running only #include <FreqCount.h> returns:

In file included from C:\Users\cschmidt\Documents\Arduino\libraries\FreqCount\FreqCount.cpp:27:
C:\Users\cschmidt\Documents\Arduino\libraries\FreqCount/util\timers.h:4: fatal error: avr/io.h: No such file or directory
compilation terminated.

I checked, and indeed there is no timers.h in util for the Arduino 1.5.2 install that I have. I tried a few other libraries of similar function, and got similar errors; one was looking for avr/interrupt.h

It seems like a version issue, where header and cpp files are calling for things that don’t exist in 1.5.2

Should I drop in these files from previous releases of the Arduino software?
Is anyone aware of a Due specific frequency counter with ~1Hz resolution across its range?