CXX-170 Backport server 2.6.0-rc3..2.6.0 changes

Author: acmorrow

src/mongo/util/version.cpp

@@ -31,7 +31,7 @@ namespace mongo {
  * 1.2.3-rc4-pre-
  * If you really need to do something else you'll need to fix _versionArray()
  */
- const char versionString[] = "2.6.0-rc3";
+ const char versionString[] = "2.6.0";
 
  // See unit test for example outputs
  BSONArray toVersionArray(const char* version){