Adding NXF_DIST launcher variable #954

This commit add the variable NXF_DIST that allows
the control on the installation path of the NF main
jar file.

nextflow

@@ -21,6 +21,7 @@ NXF_HOME=${NXF_HOME:-$HOME/.nextflow}
 NXF_PROT=${NXF_PROT:-'https'}
 NXF_BASE=${NXF_BASE:-$NXF_PROT://www.nextflow.io/releases}
 NXF_TEMP=${NXF_TEMP:-$TMPDIR}
+NXF_DIST=${NXF_DIST:-$NXF_HOME/framework}
 NXF_CLI="$0 $@"
 
 export NXF_CLI
@@ -214,7 +215,7 @@ while [[ $# != 0 ]]; do
       ;;
     -download)
       if [[ ! "$cmd" ]]; then
-      rm -rf "$NXF_HOME/framework/$NXF_VER" || exit $?
+      rm -rf "$NXF_DIST/$NXF_VER" || exit $?
       bash "$0" -version || exit $?
       exit 0
       fi
@@ -263,7 +264,7 @@ CAPSULE_CACHE_DIR=${CAPSULE_CACHE_DIR:="$NXF_HOME/capsule"}
 NXF_PACK=one
 NXF_MODE=${NXF_MODE:-''}
 NXF_JAR=${NXF_JAR:-nextflow-$NXF_VER-$NXF_PACK.jar}
-NXF_BIN=${NXF_BIN:-$NXF_HOME/framework/$NXF_VER/$NXF_JAR}
+NXF_BIN=${NXF_BIN:-$NXF_DIST/$NXF_VER/$NXF_JAR}
 NXF_PATH=$(dirname "$NXF_BIN")
 NXF_URL=${NXF_URL:-$NXF_BASE/v$NXF_VER/$NXF_JAR}
 NXF_GRAB=${NXF_GRAB:-''}