THRIFT-2745: c++ - fixed some unit test compilation on windows

Client: C++-Library
Patch: Sergei Nikulov

unist.h removed
THRIFT_SLEEP_USEC used instead of usleep
ERROR variable renamed to TEST_TOLERANCE

This closes #207
diff --git a/lib/cpp/test/concurrency/ThreadManagerTests.h b/lib/cpp/test/concurrency/ThreadManagerTests.h
index 4e53a2d..c08448b 100755
--- a/lib/cpp/test/concurrency/ThreadManagerTests.h
+++ b/lib/cpp/test/concurrency/ThreadManagerTests.h
@@ -33,17 +33,11 @@
 
 using namespace apache::thrift::concurrency;
 
-/**
- * ThreadManagerTests class
- *
- * @version $Id:$
- */
 class ThreadManagerTests {
 
+  static const double TEST_TOLERANCE;
+
 public:
-
-  static const double ERROR;
-
   class Task: public Runnable {
 
   public:
@@ -190,7 +184,7 @@
       error*= -1.0;
     }
 
-    bool success = error < ERROR;
+    bool success = error < TEST_TOLERANCE;
 
     std::cout << "\t\t\t" << (success ? "Success" : "Failure") << "! expected time: " << expectedTime << "ms elapsed time: "<< time01 - time00 << "ms error%: " << error * 100.0 << std::endl;
 
@@ -373,9 +367,8 @@
  }
 };
 
-const double ThreadManagerTests::ERROR = .20;
+const double ThreadManagerTests::TEST_TOLERANCE = .20;
 
 }}}} // apache::thrift::concurrency
 
 using namespace apache::thrift::concurrency::test;
-