contrib-script: make it so that you can source everywhere

the aliases are nice to have in other windows; if you want to
source it other places, we should make that possible.

contrib/startup_regtest.sh

@@ -57,11 +57,14 @@ addr=localhost:9090
 EOF
 
 # Start bitcoind in the background
-bitcoind -daemon -regtest
+test -f "$PATH_TO_BITCOIN/regtest/bitcoind.pid" || \
+	bitcoind -daemon -regtest
 
 # Start the lightning nodes
-"$PATH_TO_LIGHTNING/lightningd/lightningd" --lightning-dir=/tmp/l1-regtest
-"$PATH_TO_LIGHTNING/lightningd/lightningd" --lightning-dir=/tmp/l2-regtest
+test -f /tmp/l1-regtest/lightningd-regtest.pid || \
+	"$PATH_TO_LIGHTNING/lightningd/lightningd" --lightning-dir=/tmp/l1-regtest
+test  -f /tmp/l2-regtest/lightningd-regtest.pid || \
+	"$PATH_TO_LIGHTNING/lightningd/lightningd" --lightning-dir=/tmp/l2-regtest
 
 alias l1-cli='$PATH_TO_LIGHTNING/cli/lightning-cli --lightning-dir=/tmp/l1-regtest'
 alias l2-cli='$PATH_TO_LIGHTNING/cli/lightning-cli --lightning-dir=/tmp/l2-regtest'