improve template text

lib/templates/new_incoming_tx.plain

@@ -1,3 +1,2 @@
-copay@copay.io
+[Copay] New payment received
-[Copay] Funds received!
+A Payment has been received into your Copay wallet <%= walletName %>.
-Funds received on your wallet.

lib/templates/new_outgoing_tx.plain

@@ -1,3 +1,2 @@
-copay@copay.io
+[Copay] Payment sent
-[Copay] Transaction broadcasted!
+A Payment has been sent from your Copay wallet <%= walletName %>.
-A transaction has been broadcasted.

lib/templates/new_tx_proposal.plain

@@ -1,3 +1,2 @@
-copay@copay.io
+[Copay] New spend proposal
-[Copay] New transaction proposal!
+A new spend proposal has been created in your Copay wallet <%= walletName %> by <%= creatorName %>.
-A new transaction proposal has been created by another copayer.

lib/templates/txp_finally_rejected.plain

@@ -1,3 +1,2 @@
-copay@copay.io
+[Copay] Spend proposal rejected
-[Copay] A transaction proposal was rejected
+A spend proposal in your Copay wallet <%= walletName %> has been rejected by <%= creatorName %>.
-A transaction proposal was rejected by your copayers.