python3: Update to version 3.7.4

- Update setuptools to 40.8.0
- Update pip to 19.0.3
- Refreshed patches
- Removed 4 patches (2 of them was included in 3.7.3 and other two are
included in this release)

Makefile python3:
- Move PKG_MAINTAINER above PKG_LICENSE

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
(cherry-picked from ce769db007)

lang/python/python3/patches/017_lib2to3_fix_pyc_search.patch

@@ -1,8 +1,6 @@
-diff --git a/Lib/lib2to3/refactor.py b/Lib/lib2to3/refactor.py
-index 7841b99..1e0d3b3 100644
 --- a/Lib/lib2to3/refactor.py
 +++ b/Lib/lib2to3/refactor.py
-@@ -37,6 +37,12 @@ def get_all_fix_names(fixer_pkg, remove_prefix=True):
+@@ -37,6 +37,12 @@ def get_all_fix_names(fixer_pkg, remove_
              if remove_prefix:
                  name = name[4:]
              fix_names.append(name[:-3])