Fix typos in autogen.sh and README.md files.

Reported on GitHub through pull request #153 by Danny Hermes (dhermes).

FDW-536, Danny Hermes, reviewed and further changes by Vaibhav Dalvi.

README.md

@@ -197,7 +197,7 @@ statements for the foreign tables using the mongo_fdw.
 
 ### Connection Pooling
 The latest version comes with a connection pooler that utilizes the
-same mango database connection for all the queries in the same session.
+same MongoDB database connection for all the queries in the same session.
 The previous version would open a new [MongoDB][1] connection for every
 query. This is a performance enhancement.
 

autogen.sh

@@ -30,7 +30,7 @@ if ! [ -x "$(command -v cmake3)" ]; then
 fi
 
 ###
-# Pull the latest version of Monggo C Driver's master branch
+# Pull the latest version of Mongo C Driver's master branch
 #
 function checkout_mongo_driver
 {
@@ -42,7 +42,7 @@ function checkout_mongo_driver
 }
 
 ###
-# Pull the legacy branch from the Mongo C Driver's
+# Pull the legacy branch of the Mongo C Driver
 #
 function checkout_legacy_branch
 {