Replace 1.8-incompatible Hash#select with a Hash#reject

Replaced 1.8-incompatible Hash#select with a Hash#reject to make sure the gem still works on 1.8 (for those who still use ActiveRecord on the most popular version of Ruby).
Merge pull request #107 from kovyrin/patch-1

Replace 1.8-incompatible Hash#select with a Hash#reject 
ActiveRecord fix only as Mongoid doesn't support 1.8 anymore.
Remove nil entries from ResourceAdapter#resources_find when using mongoid
Merge pull request #108 from daviscabral/master

Remove nil entries from ResourceAdapter#resources_find when using mongoid adapter
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Merge branch 'master' of github.com:EppO/rolify
removed the redundant index for role-mongoid template, it was preventing the insertion of scoped roles. this fixes issue #109
Add tests for User#add_role method when useing Mongoid adapter and the resource is resourcifed and rolifed in the same time. issue #102
Changed use of tableize to table_name from the class object in order to work with classes that are using a namespace - fixes #75
Fixed issue with generation of join_table name.
Fixed issues with Mongoid environment by replacing table_name method with a regex
Merge pull request #110 from rschultheis/master

Issue #109: Remove redundant index on mongo-role.rb template
edited the specs to remove redundant Mongodb index
refs #110
fixed a bug with Mongoid roles removal
Merge branch 'namespace' of https://github.com/intrica/rolify into intrica-namespace
merged #111 PR
added specs to test namespace feature
works only with ActiveRecord so far
refs #75
edited specs for namespace support
make #112 pass the specs
closes #75
Merge branch 'master' of https://github.com/amer/rolify into amer-master
edited specs for #111 and #102
added specs for mongoid
added optional argument on resourcify method to change the role association name on the resource model