Flexibilize MMGBSA Part 2: Post-processing.

[diegoenry]

1. Choice of implicit model:
   igb=2,5,8 for GBSA
   igb=1,3 for PBSA.

2. Choice of interval:
   Default 10.

Input file for running GB2
&general
verbose=0,keep_files=0,interval=${INTERVAL}
/
&gb
igb=${IGB}, saltcon=0.150
/