RCP: 0.7.8, Rserve launch process

Replace current launch process :
1- run R and Rserve
2- connect to Rserve

With
1- run R with “R —version” and check return code
2- run R and Rserve with “R CMD ‘library(Rserve);Rserve();’”
3- connect to Rserve

Error messages:
1en- Could not start R with the following command line “…” (see TXM > Advanced >StatEngine preferences)
1fr-
2en- Could not start Rserve within R with the following command line “…” (see TXM >Advanced >StatEngine preferences)
2fr-
2en- Could not connect to R using parameters user@localhost:8854 (see TXM >Advanced >StatEngine preferences)
2fr-

(from redmine: issue id 2182, created on 2017/05/04 by Matthieu Decorde)