[core] add li_value_new_hashtable to create a GString -> liValue hashtable
[mod_vhost] convert to handling key-value list; make vhost.map_regex predictable

  vhost.map_regex used to reorder the list to put often used entries at
  the top; now it just uses the first matching entry.

  new syntax now uses the default keyword for default entries instead of
  the string "default".
[plugin_core] log/setup log: convert to handling key-value list
[mod_auth] convert to handling key-value list
[core] handle NULL values in li_value_extract* functions
[tests] run config test with valgrind too if enabled
[mod_lua] convert to handling key-value list
[core] li_value_to_string: use => for separating hash keys and values like the config
[mod_deflate] convert to handling key-value list
[mod_memcached] convert to handling key-value list
[tests] add a stub python memcached server, add mod_memcached tests
[tests] put scgi application into separate file