SPARK-1727. Correct small compile errors, typos, and markdown issues in (primarly) MLlib docs

While play-testing the Scala and Java code examples in the MLlib docs, I noticed a number of small compile errors, and some typos. This led to finding and fixing a few similar items in other docs.

Then in the course of building the site docs to check the result, I found a few small suggestions for the build instructions. I also found a few more formatting and markdown issues uncovered when I accidentally used maruku instead of kramdown.

Author: Sean Owen <sowen@cloudera.com>

Closes #653 from srowen/SPARK-1727 and squashes the following commits:

6e7c38a [Sean Owen] Final doc updates - one more compile error, and use of mean instead of sum and count
8f5e847 [Sean Owen] Fix markdown syntax issues that maruku flags, even though we use kramdown (but only those that do not affect kramdown's output)
99966a9 [Sean Owen] Update issue tracker URL in docs
23c9ac3 [Sean Owen] Add Scala Naive Bayes example, to use existing example data file (whose format needed a tweak)
8c81982 [Sean Owen] Fix small compile errors and typos across MLlib docs

1 files changed, 5 insertions, 5 deletions

diff --git a/docs/configuration.md b/docs/configuration.md
index d6f316ba5f..5b034e3cb3 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -26,10 +26,10 @@ application name), as well as arbitrary key-value pairs through the `set()` meth
 initialize an application as follows:
 
 {% highlight scala %}
-val conf = new SparkConf()
-             .setMaster("local")
-             .setAppName("My application")
-             .set("spark.executor.memory", "1g")
+val conf = new SparkConf().
+             setMaster("local").
+             setAppName("My application").
+             set("spark.executor.memory", "1g")
 val sc = new SparkContext(conf)
 {% endhighlight %}
 
@@ -318,7 +318,7 @@ Apart from these, the following properties are also available, and may be useful
     When serializing using org.apache.spark.serializer.JavaSerializer, the serializer caches
     objects to prevent writing redundant data, however that stops garbage collection of those
     objects. By calling 'reset' you flush that info from the serializer, and allow old
-    objects to be collected. To turn off this periodic reset set it to a value of <= 0.
+    objects to be collected. To turn off this periodic reset set it to a value &lt;= 0.
     By default it will reset the serializer every 10,000 objects.
   </td>
 </tr>