improving movepars function, minor fixes

Thanks to Hui-Hua Lee for helping find the issue.
Revert "Improved documentation of SSplotMovementRates and update_r4ss_files,"

This reverts commit d1ace8a142aa2705821eb85fa2938162dae23faf.
Revert "Revert "Improved documentation of SSplotMovementRates and update_r4ss_files,""

This reverts commit 614959068cf10909ea9293148ae02bdc7a4a1224.
Merge remote-tracking branch 'origin/master'