Switch from biased interpolations to reducing the order of
interpolations near surfaces
Only change igc, jgc if spatialorder=2
Only use 4th order interpolation for the advected quantity
Merge remote-tracking branch 'upstream/master' into 2i4

Conflicts:
	src/advec_2i4.cxx
Cleanup, leave the other old functions for now for testing purposes
Added base state density to 2i4 advection
Added cuda version of 2i4 advection
Use precompiler statements in fd file to allow for usage in CPU and GPU
code
Made the fd header work with both GPU and CPU code
Increased the performance of the pressure solver by defining selective
boundaryCyclic routine that can do only north-south or east-west
Remove static const definitions as IBM compiler does not allow them
Merge branch 'masterupstream' into boundarycyclic
Made the code run on juqueen again
Enable faster communications in 2nd order pressure solver
Removed define from fields
Removed all defines for constant variables
Prevent potential deadlock in failing write of time data