Add tools/install_pip.sh

Install a known working recent version of pip that handles installation
dependencies more correctly than before.  Extract to a separate script
so it can be used apart from stack.sh.

* Install distro setuptools if it not already present
* Install pip from source tarball as get-pip.py proved to be unreliable
* Remove python-distribute and python-pip from all prereq files,
  move python-setuptools to 'general'
* Remove the earlier unfubar_setuptppls() call that attenpted to fix this
* Only update requirements.txt when no changes in repo

Tested on Precise, F18 and CentOS6.
* Fedora and RHEL allow pip to install packages ON TOP OF RPM-installed
  packages.  THIS IS BROKEN.  And is one reason we have to be so picky
  about order and so forth.

Change-Id: Ibb4b42119dc2e51577c77bbbbffb110863e5324d
diff --git a/files/rpms/general b/files/rpms/general
index 9fa305c..2db31d1 100644
--- a/files/rpms/general
+++ b/files/rpms/general
@@ -11,7 +11,7 @@
 libxslt-devel # dist:rhel6 [2]
 psmisc
 pylint
-python-pip
+python-setuptools
 python-prettytable # dist:rhel6 [1]
 python-unittest2
 python-virtualenv
diff --git a/files/rpms/keystone b/files/rpms/keystone
index 33a4f47..52dbf47 100644
--- a/files/rpms/keystone
+++ b/files/rpms/keystone
@@ -4,10 +4,9 @@
 python-paste-deploy #dist:f16,f17,f18,f19
 python-paste-script #dist:f16,f17,f18,f19
 python-routes
-python-setuptools   #dist:f16,f17,f18,f19
 python-sqlalchemy
 python-sqlite2
 python-webob
 sqlite
 
-# Deps installed via pip for RHEL
\ No newline at end of file
+# Deps installed via pip for RHEL
diff --git a/files/rpms/ryu b/files/rpms/ryu
index 0f62f9f..e8ed926 100644
--- a/files/rpms/ryu
+++ b/files/rpms/ryu
@@ -1,5 +1,4 @@
 python-gevent
 python-gflags
 python-netifaces
-python-setuptools #dist:f16,f17,f18,f19
 python-sphinx
diff --git a/files/rpms/swift b/files/rpms/swift
index 2cc4a0b..b137f30 100644
--- a/files/rpms/swift
+++ b/files/rpms/swift
@@ -10,7 +10,6 @@
 python-netifaces
 python-nose
 python-paste-deploy # dist:f16,f17,f18,f19
-python-setuptools   # dist:f16,f17,f18,f19
 python-simplejson
 python-webob
 pyxattr