Fixing typos and making a sentence clearer

The sentence used to say "One difference with Try is that you can choose another type than Throwable to represent the exception," which makes it sound like you can choose types other than Throwable with Try when it is really talking about Either.

Author: CaileenD

src/main/scala/scalatutorial/sections/StandardLibrary.scala

@@ -235,7 +235,7 @@ object StandardLibrary extends ScalaTutorialSection {
    *  - or a `Failure`.
    *
    * The key difference between `None` and `Failure`s is that the latter provide
-   * the reason of the failure:
+   * the reason for the failure:
    *
    * {{{
    *   def sqrt(x: Double): Try[Double] =
@@ -249,7 +249,7 @@ object StandardLibrary extends ScalaTutorialSection {
    * be decomposed using pattern matching.
    *
    * `Try[A]` also have `map`, `filter` and `flatMap`. They behave the same
-   * as with `Option[A]`, excepted that any exception that is thrown
+   * as with `Option[A]`, except that any exception that is thrown
    * during their execution is converted into a `Failure`.
    *
    * == Either ==
@@ -259,8 +259,8 @@ object StandardLibrary extends ScalaTutorialSection {
    * of type `B`. It can be decomposed in two cases: `Left` or `Right`.
    *
    * You can use one case to represent the failure and the other to represent
-   * the success. One difference with `Try` is that you can choose another
-   * type than `Throwable` to represent the exception. Another difference
+   * the success. What makes it different from `Try` is that you can choose a
+   * type other than `Throwable` to represent the exception. Another difference
    * is that exceptions that occur when transforming `Either` values are
    * not converted into failures.
    *