fixed LaTex errors in doxygen documentation by inserting whitespaces

after and before the /f$ in the code (??) - sometimes it also works
without them, but I could not find out why or when...


git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@7867 2fb0f335-1f38-0410-981e-8018bf24f1b0

dumux/freeflow/stokes/stokesfluxvariables.hh

@@ -189,21 +189,21 @@ public:
     { return pressureAtIP_; }
 
     /*!
-     * \brief Return the mass density \f$\mathrm{[kg/m^3]}\f$ at the integration
+     * \brief Return the mass density \f$ \mathrm{[kg/m^3]} \f$ at the integration
      *        point.
      */
     Scalar densityAtIP() const
     { return densityAtIP_; }
 
     /*!
-     * \brief Return the viscosity \f$\mathrm{[m^2/s]}\f$ at the integration
+     * \brief Return the viscosity \f$ \mathrm{[m^2/s]} \f$ at the integration
      *        point.
      */
     Scalar viscosityAtIP() const
     { return viscosityAtIP_; }
 
     /*!
-     * \brief Return the normal velocity \f$\mathrm{[m/s]}\f$ at the integration
+     * \brief Return the normal velocity \f$ \mathrm{[m/s]} \f$ at the integration
      *        point.
      */
     Scalar normalVelocityAtIP() const

dumux/freeflow/stokes/stokesvolumevariables.hh

@@ -162,7 +162,7 @@ public:
     { return fluidState_.temperature(phaseIdx); }
 
     /*!
-     * \brief Returns the viscosity \f$\mathrm{[m^2/s]}\f$ of the fluid in
+     * \brief Returns the viscosity \f$ \mathrm{[m^2/s]} \f$ of the fluid in
      *        the sub-control volume.
      */
     Scalar viscosity() const