New inter-chain inerface

Several bug fixes and output of between-chain residue contact scores.

new POPScomp Docker image based on current rocker/shiny

Improved Dockerfile; new Docker image at
https://hub.docker.com/r/jkleinj150999/popscomp

run ID

Added a 'run ID' random string that is updated upon changes in any of the input parameters.
The 'run ID' identifies uniquely a given run and is used as label for the output directory and all downloadable (zip and csv) files.

Standalone

Added standalone R script with POPSCOMP functionality that is intended for use without the Shiny app and instead on the command line.

Unspecified chain identifier ' ' replaced by '-'.

Unspecified chain identifier ' ' is replaced by '-' character in "pops.out" for compatibility with the POPSR interface.

Fixed multi-chain bug

Fixed error when processing complex with multiple (>2) chains.
Additionally, added precautionary argument to system calls to wait for completion before continuing in R.

Fully documented

v3.1.5

remooved sensitive file