Sqlite::truncate(): Verify `sqlite_sequence` exists before _execute()

`sqlite_sequence` is a dynamic table that's only available when a table in
the database use an auto increment field.  For some cases, eg: databases that
exclusively use uuid for primary keys, this table won't exist and
truncate() call will fail with:

  Error: SQLSTATE[HY000]: General error: 1 no such table: sqlite_sequence
Reduce variable use/duplicate code.
Added/removed newlines to make the code more readable.
flushMethodCache not working if called before cacheMethod

When calling flushMethodCache it correctly empties self::$methodCache but if cacheMethod is called afterwards self::$methodCache gets populated with data from the Cache.
Test case for DboSource::flushMethodCache
Capitalize UUID acronym
Merge pull request #1714 from bcrowe/hotfix-uuid

Capitalize UUID acronym
Correct argument order.
Additional Cake references to CakePHP and docblock typo
Revert Cake to CakePHP in ShellDispatcher::_initEnvironment()
Prevent name param from overwriting file if both are passed
Merge pull request #1716 from ricog/schema-name-and-file

SchemaShell: Prevent name param from overwriting file param if both are passed

Fixes #4134.
Merge pull request #1715 from bcrowe/hotfix-docblocks

Additional Cake references to CakePHP and docblock typo.
Update UUID pattern to accept the 'nil' UUID.

Fixes #4133
Use App.base when there are no requests to generate URL's

Setting App.fullBaseUrl to a non-host value causes issues generating
URL's in a web context. However, not including the base path generates
incorrect URL's in a CLI context. This change allows the use of App.base
to populate the base path which is used as a fallback when there are no
requests, or when the base path is empty.

Refs #2931
Merge pull request #1718 from cakephp/issue-2931

Use App.base when there are no requests to generate URL's

Fixes #2931
Merge pull request #1593 from kimegede/more-readable-code

More readable code
Merge pull request #1546 from rchavik/2.3-sqlite-truncate

Sqlite::truncate(): Verify `sqlite_sequence` exists before _execute()
Merge pull request #1631 from ovidiupruteanu/patch-2

flushMethodCache not working if called before cacheMethod
Fixing CS