Refactoring the database layer so that query values are bound using the
query object instead to each individual expression.

This make unit testing easier for both the core and in userland, also
simplifies some routines by making them more explicit and profits from
a small performance gain.
Fixing coding style
Documenting and cleaning up, adding missing file
Fixing doc blocks
More doc block fixes
Relaxing usage for Query::bind() and adding unit test for it
Comparing numbers correctly in ValuBinder
Merge pull request #1479 from cakephp/3.0-database-bind

Changing the database layer so that the Query is responsible for binding values