put numeric helper functions into numerics.hpp to make them reusable
read EXTPAR entry 0 (fixed high-scale parameter input scale)
put the test routines into the flexiblesusy namespace
rename variable
add fixed-scale option to the high-scale constraint

If the high-scale is set to a non-zero value via set_scale(), this
scale will be used as high-scale.  This means that gauge-coupling
unification is not enforced.
pass value of EXTPAR entry 0 (input scale) to the spectrum generator

Now the user can set the parameter input scale (= gut scale) in the
SLHA file via

  Block EXTPAR
      0   0
add default setting of parameter input scale to the SLHA files
Merge branch 'master' into eigen-matrices