[Espressomd-maintainer] [espresso] LB pressure calculation and testscase (#72)

[kessel]

and added a quite powerful testcase that
checks Couette and Poisseuille flow and
hydrostatic pressure in planar geometries

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You can merge this Pull Request by running

  git pull https://github.com/kessel/espresso master

Or view, comment on, or merge it at:

  https://github.com/espressomd/espresso/pull/72

Commit Summary

• fixed the pressure tensor calculation for LB

File Changes

• M src/lb-boundaries.h (2)
• M src/lb.c (70)
• M src/lb.h (287)
• M testsuite/Makefile.am (1)
• A testsuite/lb_planar.tcl (225)

Patch Links:

• https://github.com/espressomd/espresso/pull/72.patch
• https://github.com/espressomd/espresso/pull/72.diff