fix MPI_Isend/MPI_Irecv tag may be larger then maximum allowed; more memory optimizations in multilevel solver

Functions to remove and restore upper/lower adjacency connections; use RestoreCellNodes for vtk/vtu output only; change RestoreCellNodes algorithm to not require upper adjacencies for nodes

remove Examples/TestSuite (moved to separate reposetory); fix some more warnings; processing of data for webgl in DrawGrid

fix normal orientation loss during mesh modification; function to check for cell convexity; add topology check for cell convexity; topology checks for modified elemetns; faster algorithms for orientation calculation; fixes for algorithms in modification state

fix ElementSet::SynchronizeSetElements did not connect elements to well; add ElementSet::SynchronizeSetElementsWithOwner to gather all set elements on owner only

Adapt library and examples for 64-bit integer option (USE_INT64=ON); adapt library (but not yet examples) for 32-bit float option (USE_FP64=OFF); make gcc happy on library compilation  with -Wall -Wextra -pedantic; replace malloc/realloc/free with new/delete in container.hpp