Add common is_installed() fn, better uninstall logging, check for errors.

The installer and ipactl used two different methods to determine
whether IPA was configured, unify them.

When uninstalling report any thing that looks suspicious and warn
that a re-install may fail. This includes any remaining 389-ds instances
and any state or files that remains after all the module uninstallers
are complete.

Add wrappers for removing files and directories to log failures.

https://fedorahosted.org/freeipa/ticket/1715

ipaserver/install/dsinstance.py

@@ -66,42 +66,24 @@ def schema_dirname(serverid):
     return config_dirname(serverid) + "/schema/"
 
 def erase_ds_instance_data(serverid):
-    try:
-        shutil.rmtree("/etc/dirsrv/slapd-%s" % serverid)
-    except:
-        pass
-    try:
-        shutil.rmtree("/usr/lib/dirsrv/slapd-%s" % serverid)
-    except:
-        pass
-    try:
-        shutil.rmtree("/usr/lib64/dirsrv/slapd-%s" % serverid)
-    except:
-        pass
-    try:
-        shutil.rmtree("/var/lib/dirsrv/slapd-%s" % serverid)
-    except:
-        pass
-    try:
-        shutil.rmtree("/var/lock/dirsrv/slapd-%s" % serverid)
-    except:
-        pass
-    try:
-        os.unlink("/var/run/slapd-%s.socket" % serverid)
-    except:
-        pass
-    try:
-        shutil.rmtree("/var/lib/dirsrv/scripts-%s" % serverid)
-    except:
-        pass
-    try:
-        os.unlink("/etc/dirsrv/ds.keytab")
-    except:
-        pass
-    try:
-        os.unlink("/etc/sysconfig/dirsrv-%s" % serverid)
-    except:
-        pass
+    installutils.rmtree("/etc/dirsrv/slapd-%s" % serverid)
+
+    installutils.rmtree("/usr/lib/dirsrv/slapd-%s" % serverid)
+
+    installutils.rmtree("/usr/lib64/dirsrv/slapd-%s" % serverid)
+
+    installutils.rmtree("/var/lib/dirsrv/slapd-%s" % serverid)
+
+    installutils.rmtree("/var/lock/dirsrv/slapd-%s" % serverid)
+
+    installutils.remove_file("/var/run/slapd-%s.socket" % serverid)
+
+    installutils.rmtree("/var/lib/dirsrv/scripts-%s" % serverid)
+
+    installutils.remove_file("/etc/dirsrv/ds.keytab")
+
+    installutils.remove_file("/etc/sysconfig/dirsrv-%s" % serverid)
+
 #    try:
 #        shutil.rmtree("/var/log/dirsrv/slapd-%s" % serverid)
 #    except:
@@ -114,6 +96,7 @@ def check_existing_installation():
 
     serverids = []
     for d in dirs:
+        logging.debug('Found existing 389-ds instance %s' % d)
         serverids.append(os.path.basename(d).split("slapd-", 1)[1])
 
     return serverids
@@ -674,10 +657,7 @@ class DsInstance(service.Service):
 
         if user_exists == False:
             pent = pwd.getpwnam(DS_USER)
-            try:
-                os.unlink("/var/tmp/ldap_%d" % pent.pw_uid)
-            except:
-                pass
+            installutils.remove_file("/var/tmp/ldap_%d" % pent.pw_uid)
             try:
                 ipautil.run(["/usr/sbin/userdel", DS_USER])
             except ipautil.CalledProcessError, e: