update meson build to better detect gsl

meson.build

@@ -202,7 +202,8 @@ endif
 
 ############################################################
 # dependencies that have pkg-config
-libgsl_dep = dependency('gsl')
+libgsl_dep = compiler.find_library('gsl',required: true)
+
 
 ############################################################
 # dependencies that usually have no pkg-config
@@ -315,8 +316,9 @@ foreach idir : [
                 '/usr/local/include',
                 ]
   inc_arg = idir
+  _Inc_arg = '-I' + idir
   if not found and compiler.has_header('gsl/gsl_blas.h',
-                                       args: inc_arg)
+                                       args: _Inc_arg)
     my_incdirs += [inc_arg]
     found = true
   endif

src/disc/disc_new_zone_list.c

@@ -9,7 +9,7 @@ Boolean disc_new_zone_list(struct disc_t * const disc,
      * 
      * The prefactors and exponents are defined in disc_thermal_zones.h
      *
-     * Returns FALSE on failure, TRUE otherwise.
+     * Returns FALSE on failure, TRUE on success.
      *
      * The parameter Tvisc0, which determines sigma0, hence the
      * mass scaling, determines the profile of temperature in the disc.