fix warning
Fixes #296 and update #305:
 - implement constant per case in file @dolleg
 - implement FILE_INDEX support which needs support
update #305
 - implement FileIndex helper class to read/write FILE_INDEX
Uses #296 and #305 new features
up file_index work
up #351 :
 - detect that we are on fermi and setup cmake environment
 - provide some scripts to recompile the basic feel++ dependencies
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
up #351
 - do not require lapack
 - minor change when trying to find eigen3
up #351
 - do not try to help cmake finding mpi
 - set blas and lapack using petsc
up #351:
 - build libraries in static mode add FEELPP_USE_STATIC_LINKAGE
 - introduce FEELPP_USE_CLANG_LIBCXX to set either libstdc++ or libc++ as the
 c++ library to be used
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
Merge branch 'develop' into feature/ensight

Conflicts:
	testsuite/feeldiscr/test_mortar.cpp
up #326
 - start work on MPIIO in ensight gold format
 - for the moment use MACRO to select MPIIO mode
Merge remote-tracking branch 'origin' into feature/ensight
up #326
 - added mpi-io detection (I had this in a stash)
up #326
 - fix compilation
up #326
 it seems that SOURCES in TRY_COMPILE is only in recent version of cmake
up #326 add missing file
Fixing ensight gold exporter
Merge branch 'feature/ensight' of https://github.com/feelpp/feelpp into feature/ensight