PY-29779 Bundle the most recent versions of pip and setuptools

using those included in virtualenv 16.0.0 as the baseline.

Since pip 10.0.0 has dropped support of Python 2.6 and we plan to
keep it until PyCharm 2019.1, now we need to bundle older compatible
versions of all related packages as we previously did for Python <= 2.5.

(cherry picked from commit bff4ba25)

python/src/com/jetbrains/python/packaging/PyPackageManagerImpl.java

@@ -51,10 +51,12 @@ public class PyPackageManagerImpl extends PyPackageManager {
   private static final String PIP_PRE_26_VERSION = "1.1";
   private static final String VIRTUALENV_PRE_26_VERSION = "1.7.2";
 
-  private static final String SETUPTOOLS_VERSION = "39.0.1";
+  private static final String SETUPTOOLS_VERSION = "39.1.0";
   private static final String SETUPTOOLS_VERSION_26 = "36.8.0";
-  private static final String PIP_VERSION = "9.0.3";
-  private static final String VIRTUALENV_VERSION = "15.2.0";
+  private static final String PIP_VERSION = "10.0.1";
+  private static final String PIP_VERSION_26 = "9.0.3";
+  private static final String VIRTUALENV_VERSION = "16.0.0";
+  private static final String VIRTUALENV_VERSION_26 = "15.2.0";
 
   private static final int ERROR_NO_SETUPTOOLS = 3;
 
@@ -93,15 +95,15 @@ public class PyPackageManagerImpl extends PyPackageManager {
     final Sdk sdk = getSdk();
     final LanguageLevel languageLevel = PythonSdkType.getLanguageLevelForSdk(sdk);
     final boolean pre26 = languageLevel.isOlderThan(LanguageLevel.PYTHON26);
+    final boolean py26 = languageLevel == LanguageLevel.PYTHON26;
     if (!refreshAndCheckForSetuptools()) {
-      final boolean py26 = languageLevel == LanguageLevel.PYTHON26;
       final String name = PyPackageUtil.SETUPTOOLS + "-" + (pre26 ? SETUPTOOLS_PRE_26_VERSION :
                                                             py26 ? SETUPTOOLS_VERSION_26 :
                                                             SETUPTOOLS_VERSION);
       installManagement(name);
     }
     if (PyPackageUtil.findPackage(refreshAndGetPackages(false), PyPackageUtil.PIP) == null) {
-      final String name = PyPackageUtil.PIP + "-" + (pre26 ? PIP_PRE_26_VERSION : PIP_VERSION);
+      final String name = PyPackageUtil.PIP + "-" + (pre26 ? PIP_PRE_26_VERSION : py26 ? PIP_VERSION_26 : PIP_VERSION);
       installManagement(name);
     }
   }
@@ -321,7 +323,8 @@ public class PyPackageManagerImpl extends PyPackageManager {
       }
       args.add(destinationDir);
       final boolean pre26 = languageLevel.isOlderThan(LanguageLevel.PYTHON26);
-      final String name = "virtualenv-" + (pre26 ? VIRTUALENV_PRE_26_VERSION : VIRTUALENV_VERSION);
+      final boolean py26 = languageLevel == LanguageLevel.PYTHON26;
+      final String name = "virtualenv-" + (pre26 ? VIRTUALENV_PRE_26_VERSION : py26 ? VIRTUALENV_VERSION_26 : VIRTUALENV_VERSION);
       final String dirName = extractHelper(name + ".tar.gz");
       try {
         final String fileName = dirName + name + File.separatorChar + "virtualenv.py";