bug fix for gpu attenuation routines; adds header info to gpu kernel file generation; updates file outputs to unit 10, fix in adios AVS_DX routine
bug fix for gpu output infos for displacement and strain when checking norm of arrays
Rename C I/O file to better indicate its usage.
Fix file mode in open_file_abs_r_fbin.

It should be read-only, not update.
added comments about the fact that one needs to run "configure" with option --disable-vectorization when debugging the code with range checking on
bug fix for gpu simulations with stacey absorbing boundaries; updates gpu kernel headers
updates rules.mk in src/specfem3D to compile adios files without mpif90
added a warning about versions dot zero of a compiler
bug fix for backward/reconstructed wavefield in OpenCL simulations; updates code reformatting
Merge branch 'devel' of https://github.com/geodynamics/specfem3d_globe into devel
bug fix for kernel simulations on OpenCL devices (multiple processes and asynchronuous copy); updates Makefile and rules for OpenCL flags
adds file check_opencl_device.c in utils/ directory for OpenCL device testing
updates configuration script based on newest autoconf functions in m4/
removes trailing spaces
bug fix in gpu simulations for writing out strains; adds file helper_functions_gpu.c; makes use of gpu wrapper functions for similar CUDA/OpenCL functions (avoids many ifdef-statements, improves readability)
bug fixes combine_vol_data.F90 to be usable again with adios
prettifies code (space formatting in a slightly more consistent way)
some more code formatting; adds additional gpu wrapper functions
adds preprocessor function GPU_ERROR_CHECKING for ENABLE_VERY_SLOW_ERROR_CHECKING
Added the option to use an external source time function. The parameter EXTERNAL_SOURCE_TIME_FUNCTION has been set in constants.h.in. If this is set to true (it is false by default), a text file called stf is looked for in the data directory. This file should contain a normalized source time function, with the correct number of timesteps, which will be multiplied by the moment tensor at each timestep. Also, if the external stf is specified, the halfduration is set to 0 (not needed), and the simulation start time is set to 0 as well.