Use relative URLs, not absolute.

This helps if somebody would fork a GitHub repository, as the links
now lead to files in fork, not files in original repository. Also, it
makes more sense when reading Markdown files locally.
removed unnecesary method
simplify, clarify TextSentinel

codeclimate pointed this out. I agree it is better
to simplify and reveal intentions.
small refactor of RateLimiter for clarity
extract TopicNotifier class from topic
minor refactorings
Make pry a bit more useful
Add Site Setting allow_uncategorized_topics. Uncheck it to force people to choose a category for all new topics.
Merge pull request #896 from xtream/master

Removed unnecesary method
Change composer error message when title is too long or too short, and make sure the submit button is 'disabled' when title is too long
When a user context is present, priortize all their posts ahead of
just the topic's OP before adding more.
Extract Topic#posters_summary
Remove unused parameters from posters_summary
Updated documentation

* added RVM option for single-user install
* clarified Web Server options
* bluepill sample config: create socket directory if it doesn't exist
* add multisite.yml.production-sample
* rename production.sample.rb (OCD)
* make two database.yml samples (one for dev, one for prod)
* fixed travis build (database.yml.sample renamed)
* fix other references to database.yml.sample
* clean up 'rvm requirements' instructions as per @mpapis
Add hint on how to rebake posts
Merge pull request #900 from Supermathie/sysadmin-docs

Updated documentation
Version bump to v0.9.1
Revert "update active model serializers to latest". This introduced a regression to the SiteCustomizations part of the admin section.

This reverts commit d4360798013e754e770f136eade711ae5de93fd1.
FIX: User stream was loading the same page over and over once you scrolled past 60
items.
Sliding window rate limiting

Switched the algorithm to use a circular buffer
based on a redis list