Makes error message easier to understand.

If the host ip address is indeterminate while executing
stack.sh, an error message is displayed.  This error message
could be a source of confusion since it references localrc,
which is depreciated.

This patch makes the error message clearer and easier to
understand.  It does this by taking out the reference to
localrc.  It also points the user towards local.conf where there
are suggestions on how to set HOST_IP.

Change-Id: I41f14a2de85449d2a08ab7eb2849844a1087b147
Closes-Bug: #1290556
Add python-dev to general requirements

Package python-openstackclient depends on pycrypto, and pycrypto depends
on python-dev. Since python-openstackclient should be installed in any
case, python-dev should be in general requirements.

Change-Id: I2d6f5919bdc1175252c78cd203a8769d3892b923
Closes: bug 1292477
Merge "Add python-dev to general requirements"
Merge "Makes error message easier to understand."
Merge branch 'master' of github.com:openstack-dev/devstack