up #387
 - merging eigen backend changes from explicit (d86bb36)
up #387
 - build merging-with-explicit
@asamake fix compilation
up #387
 - fix compilation
fix parallel domain decomposition

Conflicts:
	feel/feelalg/graphcsr.cpp
	feel/feelalg/matrixpetsc.cpp
	feel/feeldiscr/createsubmesh.hpp
	feel/feeldiscr/stencil.hpp
	feel/feelfilters/importergmsh.hpp

(cherry picked from commit 7ed1635fd2f93c11fe2a515b69f1b5d45d694a4c)

Conflicts:
	feel/feeldiscr/createsubmesh.hpp
up #387 : add interface for PETSc submatrix and test

Conflicts:
	feel/feelalg/matrixpetsc.cpp

(cherry picked from commit 96c1345f88dc9f9b97bfd726954cacb5641269ef)

Conflicts:
	testsuite/feelalg/CMakeLists.txt
up #387
 - add substructring to mesh

Conflicts:
	feel/feeldiscr/doftable.hpp
	quickstart/laplacian.cpp

(cherry picked from commit 8e8aef99bf26aff7079a035dc7ad51b416702e1a)

Conflicts:
	feel/feelfilters/gmsh.hpp
	feel/options.cpp
up #387 : add some interfaces

Conflicts:
	feel/feelalg/matrixsparse.hpp
	feel/feeldiscr/doftable.hpp

(cherry picked from commit 2ca462c623a5bd2606c623d2caf676b82c29b58c)

Conflicts:
	feel/feelalg/matrixeigendense.cpp
	feel/feeldiscr/doftable.hpp
up #387: new interface for sqrt matrix

Conflicts:
	feel/feelalg/matrixeigendense.cpp
	feel/feelalg/matrixsparse.hpp

(cherry picked from commit 6dcd7d85368d80b7beee32b5ba9295de9a124a66)

Conflicts:
	feel/feelalg/matrixeigendense.cpp
up #387: container depends to backend

(cherry picked from commit bd2e1cad1f5d81abb2bc1bf7165124ac87aaf51c)
uo #387
 - fix compilation of testsuite
up #387: fix communicator
up #387 : added eigenValues() computation in dense eigen
up #387 : fix explicit parallelism

Conflicts:
	doc/manual/laplacian/CMakeLists.txt
	feel/feelalg/backendeigen.hpp
	feel/feelalg/matrixsparse.hpp

(cherry picked from commit 12e37be91e7a29baaaaea2d9bd19b2bb11175a44)

Conflicts:
	feel/feelalg/matrixeigendense.hpp
	feel/options.cpp
Merge branch 'merging-with-explicit' of https://github.com/feelpp/feelpp into merging-with-explicit
up #387 : deduce mesh size from nx and ny

(cherry picked from commit 21755fb5b67b7c55c5145dc553ab5e6220e603c5)

Conflicts:
	feel/feelfilters/gmsh.hpp
fix compilation
up #387 : added worldcomm
up #387: Add symmetry tests for sparse matrices

(cherry picked from commit 5e562e7a2701df0639ce633d55b74639e0d9683b)

Conflicts:
	feel/feelalg/matrixsparse.hpp
add -VV to travis checks to have more information if tests are failing