Add View::exists() and View::getRegisteredEngines()

Close #1707
Test cases for #1707
Updated CHANGELOG
Added Phalcon\Mvc\Router\Route::getGroup()

Close #1682
Phalcon\Mvc\Router\Group optimization
Test case for #1682
Updated CHANGELOG
Phalcon\Logger\Adapter optimization
Do not install DI's get_properties handler if NuSpehere DBG is used

Fix #1714
Fix #1716
Test case for #1716
Updated CHANGELOG
Updated CHANGELOG
Merge pull request #1713 from sjinks/issue-1707

Add View::exists() and View::getRegisteredEngines()
Merge pull request #1715 from sjinks/issue-1682

Add Phalcon\Mvc\Router\Route::getGroup()
PDO/Adapter updates from 1.2.5:
- added tinyint(1) as boolean for mysql, oracle, postresql, sqlite.
- added timestamp as date for mysql.
- decribeColumns method has been refactored in oracle, postesql, sqlite.
- added constraint creation for foreign key
Missed unit-tests/DbDialectTest.php.
Merge pull request #1719 from lantian/1.3.0

PDO/Adapter updates from 1.2.5
Merge pull request #1720 from sjinks/issue-1716

Phalcon\Logger\Adapter::setLogLevel() should be honored by transactions
Merge pull request #1721 from sjinks/issue-1714

Workarounds for NuSphere DBG