add support for defining custom keywords mappings in configuration file

This can be used for shortcuts or alternative names, ex:

 [keywords]
 monitoring = munin,scrutiny,prometheus

or to prevent common errors or misconceptions:

 [keywords]
 saas/test = saas/test,-hds,-re,-docbow

README

@@ -38,6 +38,18 @@ It is also possible to declare additional servers, in a [servers] section, ex::
  host.domain = keyword1, keyword2
 
 
+And custom keywords mapping can be defined, for shortcuts or alternative names,
+ex::
+
+ [keywords]
+ monitoring = munin,scrutiny,prometheus
+
+or to prevent common errors or misconceptions::
+
+ [keywords]
+ saas/test = saas/test,-hds,-re,-docbow
+
+
 Examples
 --------
 

eoptasks.py

@@ -124,12 +124,15 @@ def parse_args():
 def filter_servers(servers, args):
     selected_servers = []
     if args.keywords:
-        for keyword in args.keywords.split(','):
+        config = get_config()
+        cmd_keywords = config['keywords'].get(args.keywords, args.keywords)
+
+        for keyword in cmd_keywords.split(','):
             keywords = set(keyword.split('/'))
             selected_servers.extend(
                 [x for x in servers if keywords.issubset(x.keywords) and not x in selected_servers]
             )
-        for keyword in args.keywords.split(','):
+        for keyword in cmd_keywords.split(','):
             if keyword.startswith('!') or keyword.startswith('-'):
                 selected_servers = [x for x in selected_servers if keyword[1:] not in x.keywords]
     else: