switched filterstream user to associated twitter_filter.user, refs #174
updated TwitterFilter help text to state "space-separated", not comma-, refs #174
added user to TwitterFilterAdmin, refs #174
Merge branch 't130-generate-process-conf' of https://github.com/gwu-libraries/social-feed-manager into t130-generate-process-conf
cleaned up filterstream to remove legacy "one big filter" logic, tightened up args/options, closes #174; cleaned up createconf to match, refs #170