[cantera2.0]: updating the doxygen headers for the GasTransport phase. It appears that the latex was written as \Sum, instead of \sum, which makes the doxygen documentation improperly render. Fixing, will check up on documentation later. This change affects methods getMixDiffCoeffsMole as well as getMixDiffCoeffsMass

include/cantera/transport/GasTransport.h

@@ -81,7 +81,7 @@ public:
     //! from the species mole fraction gradients, computed according to
     //! Eq. 12.176 in "Chemically Reacting Flow":
     //!
-    //! \f[  D_{km}^* = \frac{1-X_k}{\Sum_{j \ne k}^K X_j/\mathcal{D}_{kj}} \f]
+    //! \f[  D_{km}^* = \frac{1-X_k}{\sum_{j \ne k}^K X_j/\mathcal{D}_{kj}} \f]
     //!
     //! @param[out] d vector of mixture-averaged diffusion coefficients for
     //!     each species, length m_nsp.
@@ -92,8 +92,8 @@ public:
     //! from the species mass fraction gradients, computed according to
     //! Eq. 12.178 in "Chemically Reacting Flow":
     //!
-    //! \f[  \frac{1}{D_{km}} = \Sum_{j \ne k}^K \frac{X_j}{\mathcal{D}_{kj}} +
-    //!     \frac{X_k}{1-Y_k} \Sum_{j \ne k}^K \frac{Y_j}{\mathcal{D}_{kj}} \f]
+    //! \f[  \frac{1}{D_{km}} = \sum_{j \ne k}^K \frac{X_j}{\mathcal{D}_{kj}} +
+    //!     \frac{X_k}{1-Y_k} \sum_{j \ne k}^K \frac{Y_j}{\mathcal{D}_{kj}} \f]
     //!
     //! @param[out] d vector of mixture-averaged diffusion coefficients for
     //!     each species, length m_nsp.