Memory reduction of GMSH used as an external lib for ParaView plugin

See merge request !23

fix compile for occt 7.2

See merge request !22

fix #297

Closes #297

See merge request !21

change INP node format to %.14g so that total number of chars is <= 20 (fix #310: Calculix compatibility)

speed up entity creation for experts; it also avoids creating duplicates when not necessary)

add page up and page down shortcut for using pointers in presentations with gmsh

See merge request !20

One file per part

See merge request !19

Add a CLI option to reclassify mesh as 2d

See merge request !18

added command line interface option to: 1) write partitioned mesh to separate files. 2) Ignore periodicity information when reading a mesh.

add synonyms for boolean operations (Intersection==Common, etc.) + allow to have empty tool for fragments