add `setup.py jsversion`

for writing the IPython version to `IPython.version` in javascript.

supersedes  #4357

IPython/html/static/base/js/namespace.js

@@ -1,5 +1,5 b''
 //----------------------------------------------------------------------------
-//  Copyright (C) 2008-2011  The IPython Development Team
+//  Copyright (C) 2011  The IPython Development Team
 //
 //  Distributed under the terms of the BSD License.  The full license is in
 //  the file COPYING, distributed as part of this software.
@@ -7,6 +7,8 b''
 
 var IPython = IPython || {};
 
+IPython.version = "2.0.0-dev";
+
 IPython.namespace = function (ns_string) {
     "use strict";
 

setup.py

@@ -68,6 +68,7 b' from setupbase import ('
     require_submodules,
     UpdateSubmodules,
     CompileCSS,
+    JavascriptVersion,
     install_symlinked,
     install_lib_symlink,
     install_scripts_for_symlink,
@@ -236,6 +237,7 b" setup_args['cmdclass'] = {"
     'symlink': install_symlinked,
     'install_lib_symlink': install_lib_symlink,
     'install_scripts_sym': install_scripts_for_symlink,
+    'jsversion' : JavascriptVersion,
 }
 
 #---------------------------------------------------------------------------

setupbase.py

@@ -564,3 +564,25 b' class CompileCSS(Command):'
     
     def run(self):
         call("fab css", shell=True, cwd=pjoin(repo_root, "IPython", "html"))
+
+class JavascriptVersion(Command):
+    """write the javascript version to notebook javascript"""
+    description = "Write IPython version to javascript"
+    user_options = []
+    
+    def initialize_options(self):
+        pass
+    
+    def finalize_options(self):
+        pass
+    
+    def run(self):
+        nsfile = pjoin(repo_root, "IPython", "html", "static", "base", "js", "namespace.js")
+        with open(nsfile) as f:
+            lines = f.readlines()
+        with open(nsfile, 'w') as f:
+            for line in lines:
+                if line.startswith("IPython.version"):
+                    line = 'IPython.version = "{0}";\n'.format(version)
+                f.write(line)
+