Remove ext-mbstring dependency.

mbstring is not a hard dependency for 2.x. The Multibyte class can shim
up the missing extension.

Refs #2564
Set the default type to select.

It is the implicit default anyways. If a query object does not have
another query type method called it should behave like a select query.
This change removes annoying failures when using mocked queries.
Separate execute() into 2 methods.

Split execute() into 2 methods. ORM\Query::execute() now only ever
returns a StatementInterface, while Query::all() returns a ResultSet
object. This allows each method to have a consistent return value and
allows update/delete/insert queries to not trigger Model.beforeFind
events incorrectly.

I'm not sold on the method names, but I think the separation they create
is a useful change.
Fix merge conflict issues and failing tests.
Update some grammar in Controller
Fix failing code in PaginatorComponent.

Instead of execute(), all() should be used now.
Merge pull request #2572 from bcrowe/hotfix-controllerBlocks

Update some grammar in Controller
Merge pull request #2571 from cuppett/patch-1

Must double quote the schema name in query
Fix failing SchemaCollection tests.

I was clearing the cache incorrectly in the past.
Query::_type has to default to null.

Defaulting to 'select' causes downstream failures when identifier
quoting is involved and queries are manipulated.
Merge pull request #2578 from cakephp/3.0-orm-query-get

3.0 - Separate query->execute() & query->all()
Merge branch 'master' into 2.5

Conflicts:
	lib/Cake/VERSION.txt
Remove no-op method.

This method did nothing but heat the earth.
Changing params for callbacks in MapReduce to they are consistent with
the rest of the functions in Collection
Reversing params for mapReduce in Table class
Updating tests having calls to mapReduce to account for new parameter
order
Merge pull request #2583 from cakephp/3.0-mapreduce-params

3.0 - mapreduce params
Custom finder methods will receive the full array of extra options
passed to the query every time
Merge pull request #2587 from cakephp/3.0-pass-options

Custom finder methods will receive the full array of extra options
Add autoIncrement flag to integer & biginteger columns.

When using composite primary keys we can't just guess at which column
should be the autoincrement one. Instead we should allow the developer
to specify which one is the auto-incrementing/serial column.