Enable complex queries

[xzachtli]

Simplify query and index calls further by moving parameters into specifications object
Allow text querying by setting specifications.query
Allow for complex AND/OR queries

Added tests to verify query build operation

Fix 0 skipped results on statistics object

[xzachtli]

Further clarification:

Objects are AND-ed together and array sets are OR-ed

parameters = { name: 'steve', age: 15 } => (name:(steve) AND age:(15))

If all members of an array are objects, the original object key pointing to the array is ignored ("_or" in this case)

parameters = { _or: [ { name: 'steve' }, { age: 15 } ] } => (name:(steve) OR age:(15))

If some members of an array are not objects, the original object key is used for the filter for these items.

parameters = { name: [ 'steve', 'john', {age: 15 } ] } => (name:(steve) OR name:(john) OR age:(15))

Following these rules, you can nest objects and arrays to create complex queries.