2.0.0.0-dev38

* Changed application initialization procedure
  * Application can be started with specific initial configuration data. `Mage_Core_Model_Config::loadBase()` merges this configuration with the highest priority
  * `Mage` class is no longer responsible for application installation status. `Mage_Core_Model_App` has this responsibility (`Mage_Core_Model_App::isInstalled()`)
* Implemented new library component `Magento_Filesystem` for working with file system
  * New component has more abstract layer of interaction with file system, better path isolation
  * Introduced interface Magento_Filesystem_AdapterInterface for file operations. Added concrete implementation in `Magento_Filesystem_Adapter_Local`
  * Introduced interface Magento_Filesystem_StreamInterface for stream operations with content. Added concrete implementation in `Magento_Filesystem_Stream_Local`
  * Added special class `Magento_Filesystem_Stream_Mode` to set parameters of stream on opening (read-only, write-only etc.)
* Added an ab...