Fixes #596: Implement conjunctions and disjunctions for fulltext search
#597: Remove debugger to not break the build @ 1.8.7
Rewrite joins support to work with fulltext queries, resolves #470
Add :prefix option to resolve name conflicts (if multiple models have fields with the same name)
Move options check into a separate method
Bufgix: do not modify the source string (causes boost to be applied multiple times, e.g. field_name^2^2^2 adding it again and again with each new call)
Fix typo
Bugfix: do not mix fulltext and joined fields when adding from the fulltext DSL
Move common methods to the abstract class
Bugfix: update Field#eql? to compare fields of different classes properly
Fix 1.8 build (hash ordering issue)
Do not add empty connective to the query
Merge pull request #597 from Drakula2k/connective-fulltext

Implement conjunctions and disjunctions for fulltext search: #596