Change FreeIPA license to GPLv3+

The changes include:
 * Change license blobs in source files to mention GPLv3+ not GPLv2 only
 * Add GPLv3+ license text
 * Package COPYING not LICENSE as the license blobs (even the old ones)
   mention COPYING specifically, it is also more common, I think

 https://fedorahosted.org/freeipa/ticket/239

ipa.spec.in

@@ -17,7 +17,7 @@ Release:        __RELEASE__%{?dist}
 Summary:        The Identity, Policy and Audit system
 
 Group:          System Environment/Base
-License:        GPLv2
+License:        GPLv3+
 URL:            http://www.freeipa.org/
 Source0:        freeipa-%{version}.tar.gz
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -367,7 +367,7 @@ fi
 
 %if ! %{ONLY_CLIENT}
 %files server
-%doc LICENSE README Contributors.txt
+%doc COPYING README Contributors.txt
 %defattr(-,root,root,-)
 %{_sbindir}/ipa-dns-install
 %{_sbindir}/ipa-server-install
@@ -446,7 +446,7 @@ fi
 %endif
 
 %files client
-%doc LICENSE README Contributors.txt
+%doc COPYING README Contributors.txt
 %{_sbindir}/ipa-client-install
 %{_sbindir}/ipa-getkeytab
 %{_sbindir}/ipa-rmkeytab
@@ -466,7 +466,7 @@ fi
 
 %if ! %{ONLY_CLIENT}
 %files admintools
-%doc LICENSE README Contributors.txt
+%doc COPYING README Contributors.txt
 %defattr(-,root,root,-)
 %{_bindir}/ipa
 %{_sbindir}/ipa-ldap-updater
@@ -478,7 +478,7 @@ fi
 %endif
 
 %files python -f %{gettext_domain}.lang
-%doc LICENSE README Contributors.txt
+%doc COPYING README Contributors.txt
 %defattr(-,root,root,-)
 %dir %{python_sitelib}/ipapython
 %{python_sitelib}/ipapython/*.py*
@@ -493,13 +493,13 @@ fi
 
 %if %{WITH_RADIUS}
 %files radius-server
-%doc LICENSE README Contributors.txt
+%doc COPYING README Contributors.txt
 %{_usr}/share/ipa/ipaserver/plugins/*
 %dir %{_usr}/share/ipa/plugins
 %{_usr}/share/ipa/plugins/radius.radiusd.conf.template
 
 %files radius-admintools
-%doc LICENSE README Contributors.txt
+%doc COPYING README Contributors.txt
 %{_sbindir}/ipa-addradiusclient
 %{_sbindir}/ipa-addradiusprofile
 %{_sbindir}/ipa-delradiusclient