Delete empty below comments on classes and functions (#3669)

Deleting the empty lines between the Doxygen comments and the class
declarations makes Intellisense actually recognize the connections.

Author: eebasso

Src/Amr/AMReX_Amr.H

@@ -30,7 +30,6 @@ class AmrInSituBridge;
 * not belong on a single level, like establishing and updating the hierarchy
 * of levels, global timestepping, and managing the different AmrLevels
 */
-
 class Amr
     : public AmrCore
 {

Src/Amr/AMReX_AmrLevel.H

@@ -34,7 +34,6 @@ class TagBoxArray;
 * AmrLevel functions both as a container for state data on a level
 * and also manages the advancement of data in time.
 */
-
 class AmrLevel
 {
     friend class Amr;

Src/Amr/AMReX_Derive.H

@@ -100,7 +100,6 @@ class DescriptorList;
 * from the state data contained in AmrLevel and its derivatives. Some
 * examples might be kinetic energy, vorticity, concentration gradients ...
 */
-
 class DeriveRec
 {
    friend class DeriveList;
@@ -339,7 +338,6 @@ private:
 *
 * DeriveList manages and provides access to the list of DeriveRecs.
 */
-
 class DeriveList
 {
 public:

Src/Amr/AMReX_LevelBld.H

@@ -18,7 +18,6 @@ namespace amrex {
 * Abstract base class specifying an interface for building problem-specific
 * AmrLevels.
 */
-
 class LevelBld
 {
 public:

Src/Amr/AMReX_StateData.H

@@ -29,7 +29,6 @@ class StateDataPhysBCFunct;
 *
 * StateData holds state data on a level for the current and previous time step.
 */
-
 class StateData
 {
     friend class StateDataPhysBCFunct;

Src/Amr/AMReX_StateDescriptor.H

@@ -29,7 +29,6 @@ namespace amrex {
 /**
 * \brief Attributes of StateData.
 */
-
 class StateDescriptor
 {
     friend class DescriptorList;
@@ -434,7 +433,6 @@ private:
 *
 * A container class for StateDescriptors.
 */
-
 class DescriptorList
 {
 public:

Src/AmrCore/AMReX_AmrCore.H

@@ -20,7 +20,6 @@ class AmrParGDB;
  * virtual functions to allocate, initialize and delete data.  It also
  * requires the derived class to tag cells for refinement.
  */
-
 class AmrCore
     : public AmrMesh
 {

Src/AmrCore/AMReX_Cluster.H

@@ -20,7 +20,6 @@ class ClusterList;
 *
 * Utility class for tagging error cells.
 */
-
 class Cluster
 {
 public:
@@ -138,7 +137,6 @@ private:
 *
 * A container class for Cluster.
 */
-
 class ClusterList
 {
 public:

Src/AmrCore/AMReX_ErrorList.H

@@ -102,7 +102,6 @@ extern "C"
 * actual error tagging will be through derivation, so provision is made
 * for this as well.
 */
-
 class ErrorRec
 {
 public:
@@ -348,7 +347,6 @@ private:
 *
 * Container class for ErrorRecs.
 */
-
 class ErrorList
 {
 public:

Src/AmrCore/AMReX_FillPatcher.H

@@ -68,7 +68,6 @@ namespace amrex {
  * See AmrLevel::RK for an example of using the RungeKutta functions and
  * FillPatcher together.
  */
-
 template <class MF = MultiFab>
 class FillPatcher
 {