Gemfile mongoid use `:git => 'https://github.com/kfl62/mongoid.git', :branch => '3.1.0-stable'` until [mongoid issue][3] is solved
controllers: `system.rb` fix #5
models: `Trst::Firm` fix #4
models `Trst::Person` fix #6
lib: `trst_helper.rb` validation error messages bug
i18n: some translations
update CHANGELOG
bup version v0.2.15
Merge branch 'hotfix/v0.2.15'
Merge tag 'v0.2.15' into develop

Hotfix v0.2.15