Minor indentation and comment typo fixes.

Author: Aaron Staple <astaple@gmail.com>

Closes #1630 from staple/minor and squashes the following commits:

6f295a2 [Aaron Staple] Fix typos in comment about ExprId.
8566467 [Aaron Staple] Fix off by one column indentation in SqlParser.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala

@@ -210,21 +210,21 @@ class SqlParser extends StandardTokenParsers with PackratParsers {
     } |
     "(" ~> query ~ ")" ~ opt(AS) ~ ident ^^ { case s ~ _ ~ _ ~ a => Subquery(a, s) }
 
-   protected lazy val joinedRelation: Parser[LogicalPlan] =
-     relationFactor ~ opt(joinType) ~ JOIN ~ relationFactor ~ opt(joinConditions) ^^ {
+  protected lazy val joinedRelation: Parser[LogicalPlan] =
+    relationFactor ~ opt(joinType) ~ JOIN ~ relationFactor ~ opt(joinConditions) ^^ {
       case r1 ~ jt ~ _ ~ r2 ~ cond =>
         Join(r1, r2, joinType = jt.getOrElse(Inner), cond)
-     }
+    }
 
-   protected lazy val joinConditions: Parser[Expression] =
-     ON ~> expression
+  protected lazy val joinConditions: Parser[Expression] =
+    ON ~> expression
 
-   protected lazy val joinType: Parser[JoinType] =
-     INNER ^^^ Inner |
-     LEFT ~ SEMI ^^^ LeftSemi |
-     LEFT ~ opt(OUTER) ^^^ LeftOuter |
-     RIGHT ~ opt(OUTER) ^^^ RightOuter |
-     FULL ~ opt(OUTER) ^^^ FullOuter
+  protected lazy val joinType: Parser[JoinType] =
+    INNER ^^^ Inner |
+    LEFT ~ SEMI ^^^ LeftSemi |
+    LEFT ~ opt(OUTER) ^^^ LeftOuter |
+    RIGHT ~ opt(OUTER) ^^^ RightOuter |
+    FULL ~ opt(OUTER) ^^^ FullOuter
 
   protected lazy val filter: Parser[Expression] = WHERE ~ expression ^^ { case _ ~ e => e }
 

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/namedExpressions.scala

@@ -28,8 +28,8 @@ object NamedExpression {
 }
 
 /**
- * A globally (within this JVM) id for a given named expression.
- * Used to identify with attribute output by a relation is being
+ * A globally unique (within this JVM) id for a given named expression.
+ * Used to identify which attribute output by a relation is being
  * referenced in a subsequent computation.
  */
 case class ExprId(id: Long)