Moved "benchmark" tests that cannot fail (see #349) to the nightly build to reduce testing time

Author: NightOwl888

src/Lucene.Net.Tests.Analysis.Phonetic/Language/Bm/CacheSubSequencePerformanceTest.cs

@@ -28,6 +28,7 @@ public class CacheSubSequencePerformanceTest : LuceneTestCase
     {
         [Test]
         [Slow]
+        [Nightly] // LUCENENET: Since this is more of a benchmark than a test, moving to Nightly to keep us from buring testing time on it
         public void Test()
         {
             int times = 10000000;

src/Lucene.Net.Tests/Index/TestTermdocPerf.cs

@@ -1,4 +1,4 @@
-using Lucene.Net.Analysis;
+using Lucene.Net.Analysis;
 using Lucene.Net.Analysis.TokenAttributes;
 using Lucene.Net.Documents;
 using Lucene.Net.Index.Extensions;
@@ -165,6 +165,7 @@ public virtual int DoTest(int iter, int ndocs, int maxTF, float percentDocs)
 
         [Test]
         [Slow]
+        [Nightly] // LUCENENET: Since this is more of a benchmark than a test, moving to Nightly to keep us from buring testing time on it
         public virtual void TestTermDocPerf()
         {
             // performance test for 10% of documents containing a term