Update CHANGELOG
Bump to 0.5.1
show scopes even if no results are found

When using filters, the previous behavior was to hide all scopes. This
is counterintuitive, as a different scope from the current one may have
results for the selected filter, and ends up confusing the user.
add conditional :if and :unless logic to filters

+ followed the way conditional procs are built for Scopes
+ by way of Array.group_by, we now only recognize the last-defined
  `filter` call for each individual attribute
+ update the specs to allow `filter` to be called multiple times on
  the same pseudo-document
Fix conflict with Redcloth
Added powered by translation
routing fixed for Devise on root namespace
Fix typo
Added missing batch actions translations leading to no labels (see PR #1788)
Merge pull request #1814 from EtienneDepaulis/missing_batch_actions_translations

Added missing batch actions translations leading to no labels (see PR #1788)
Merge pull request #1807 from adrienkohlbecker/master

Fix #1805 conflict with Redcloth
Update CHANGELOG
Merge pull request #1810 from kieranklaassen/patch-1

Added powered by translation
Fix fields_for_params when Boolean values
Add the license identifier to the gemspec
remove duplication in ResourceDSL#*_action methods
simplify options normalization helper
refactor router
Improved Czech translation
Allow resource collections to be sorted by virtual columns