Merging DebConf changes

Credit for this patch goes to Margarita Manterola. Original patch at:

http://lists.debconf.org/lurker/message/20140904.221307.3c4b2a0c.en.html
Clarify the meaning of "requires"
Merge pull request #5 from fmarier/patch-1

Merging DebConf changesMOTION by Francois that the amendments proposed in the pull request be merged   into the DebConf policy
SECONDED by Christopher Neugebauer
CARRIED unanimously