integrate compute pressure/cylinder into build and README

src/.gitignore

@@ -296,6 +296,8 @@
 /compute_plasticity_atom.h
 /compute_pressure_bocs.cpp
 /compute_pressure_bocs.h
+/compute_pressure_cylinder.cpp
+/compute_pressure_cylinder.h
 /compute_pressure_grem.cpp
 /compute_pressure_grem.h
 /compute_rigid_local.cpp

src/USER-MISC/README

@@ -30,6 +30,7 @@ compute ackland/atom, Gerolf Ziegenhain, gerolf at ziegenhain.com, 4 Oct 2007
 compute basal/atom, Christopher Barrett, cdb333 at cavs.msstate.edu, 3 Mar 2013
 compute cnp/atom, Paulo Branicio (USC), branicio at usc.edu, 31 May 2017
 compute entropy/atom, Pablo Piaggi (EPFL), pablo.piaggi at epfl.ch, 15 June 2018
+compute pressure/cylinder, Cody K. Addington (NCSU), , 2 Oct 2018
 compute stress/mop, Romain Vermorel (U Pau) & Laurent Joly (U Lyon), romain.vermorel at univ-pau.fr & ljoly.ulyon at gmail.com, 5 Sep 18
 compute stress/mop/profile, Romain Vermorel (U Pau) & Laurent Joly (U Lyon), romain.vermorel at univ-pau.fr & ljoly.ulyon at gmail.com, 5 Sep 18
 compute temp/rotate, Laurent Joly (U Lyon), ljoly.ulyon at gmail.com, 8 Aug 11