Updates based on bitcoin-dot-org changes

- Blockchain guide typo (bitcoin-dot-org/#1920)
 - GetTxOut correction (bitcoin-dot-org/#1891)
 - Tx Guide (bitcoin-dot-org/#1819)
 - Vars.md (bitcoin-dot-org/#1825)
 - signrawtransaction typo

_includes/devdoc/dash-core/rpcs/rpcs/gettxout.md

@@ -50,7 +50,7 @@ The `gettxout` RPC {{summary_getTxOut}}
 - n: "`result`"
   t: "object/null"
   p: "Required<br>(exactly 1)"
-  d: "Information about the output.  If output wasn't found or if an error occurred, this will be JSON `null`"
+  d: "Information about the output.  If output wasn't found, if it was spent, or if an error occurred, this will be JSON `null`"
 
 - n: "→<br>`bestblock`"
   t: "string (hex)"

_includes/devdoc/dash-core/rpcs/rpcs/signrawtransaction.md

@@ -109,11 +109,10 @@ Sign the hex generated in the example section for the `createrawtransaction`
 RPC:
 
 {% highlight bash %}
-dash-cli -testnet signrawtransaction signrawtransaction 01000000016b4908\
-86c0198b028c6c5cb145c4eb3b1055a224a7a105aadeff41b69ec91e060100000000ffff\
-ffff0200205fa0120000001976a914485485425fa99504ec1638ac4213f3cfc9f32ef388\
-acc0a8f9be010000001976a914811eacc14db8ebb5b64486dc43400c0226b428a488ac00\
-000000
+dash-cli -testnet signrawtransaction 01000000016b490886c0198b028c6c5cb14\
+5c4eb3b1055a224a7a105aadeff41b69ec91e060100000000ffffffff0200205fa012000\
+0001976a914485485425fa99504ec1638ac4213f3cfc9f32ef388acc0a8f9be010000001\
+976a914811eacc14db8ebb5b64486dc43400c0226b428a488ac00000000
 {% endhighlight %}
 
 Result: