Fix building with C++14, which errors out due to collisions with the
internal log2 and log10 functions, which are now part of C++11.
See also: https://bugs.gentoo.org/show_bug.cgi?id=594692

--- a/src/hhalign/util-C.h
+++ b/src/hhalign/util-C.h
@@ -27,6 +27,7 @@
 #include <cstdio>     // printf
 #include <stdlib.h>   // exit
 #include <time.h>     // clock
+#include <math.h>
 #endif
 #include <sys/time.h>
 //#include "new_new.h" /* memory tracking */
@@ -50,10 +51,6 @@
 //// Generalized mean: d=0: sqrt(x*y)  d=1: (x+y)/2  d->-inf: min(x,y)  d->+inf: max(x,y)  
 inline double fmean(double x, double y, double d) { return pow( (pow(x,d)+pow(y,d))/2 ,1./d);}
 
-// log base 2
-inline float log2(float x)  {return (x<=0? (float)(-100000):1.442695041*log(x));}
-inline float log10(float x) {return (x<=0? (float)(-100000):0.434294481*log(x));}
-
 
 /////////////////////////////////////////////////////////////////////////////////////
 // fast log base 2