remove strict requirement for less,invoke in wheel/sdist

move the strictness to our release script

this means others can build personal wheels without less, invoke,
but IPython releases still cannot be made without them,
which is the real goal.

setup.py

@@ -216,7 +216,7 b" setup_args['cmdclass'] = {"
     'build_py': css_js_prerelease(
             check_package_data_first(git_prebuild('IPython')),
         strict=False),
-    'sdist' : css_js_prerelease(git_prebuild('IPython', sdist)),
+    'sdist' : css_js_prerelease(git_prebuild('IPython', sdist), strict=False),
     'upload_wininst' : UploadWindowsInstallers,
     'submodule' : UpdateSubmodules,
     'css' : CompileCSS,
@@ -284,7 +284,7 b" if 'setuptools' in sys.modules:"
     # setup.py develop should check for submodules
     from setuptools.command.develop import develop
     setup_args['cmdclass']['develop'] = require_submodules(develop)
-    setup_args['cmdclass']['bdist_wheel'] = css_js_prerelease(get_bdist_wheel())
+    setup_args['cmdclass']['bdist_wheel'] = css_js_prerelease(get_bdist_wheel(), strict=False)
     
     setuptools_extra_args['zip_safe'] = False
     setuptools_extra_args['entry_points'] = {'console_scripts':find_entry_points()}

tools/release

@@ -22,9 +22,11 b' if not os.path.exists(ipbackupdir):'
 cd(ipdir)
 
 # Load release info
-execfile(pjoin('IPython','core','release.py'))
+execfile(pjoin('IPython','core','release.py'), globals())
 # ensure js version is in sync
 sh('./setup.py jsversion')
+# build minified css and sourcemaps
+sh('./setup.py css -x -f')
 
 # Build site addresses for file uploads
 release_site = '%s/release/%s' % (archive, version)

tools/toollib.py

@@ -59,3 +59,10 b' def compile_tree():'
         msg = '*** ERROR: Some Python files in tree do NOT compile! ***\n'
         msg += 'See messages above for the actual file that produced it.\n'
         raise SystemExit(msg)
+
+try:
+    execfile
+except NameError:
+    def execfile(fname, globs, locs=None):
+        locs = locs or globs
+        exec(compile(open(fname).read(), fname, "exec"), globs, locs)