utility method for append path, fixes #414

test/fast/Unit tests/nvm_prepend_path

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+TEST_PATH=/usr/bin:/usr/local/bin
+
+NEW_PATH=`nvm_prepend_path "$TEST_PATH" "$NVM_DIR/v0.2.5/bin"`
+
+[ "$NEW_PATH" = "$NVM_DIR/v0.2.5/bin:/usr/bin:/usr/local/bin" ] || die "Not correctly prepended: $STRIPPED_PATH "
+
+
+EMPTY_PATH=
+
+NEW_PATH=`nvm_prepend_path "$EMPTY_PATH" "$NVM_DIR/v0.2.5/bin"`
+
+[ "$NEW_PATH" = "$NVM_DIR/v0.2.5/bin" ] || die "Not correctly prepended: $STRIPPED_PATH "