#78 Preparation and implementation of user download from server - still need more work and debugging

#68 Partial support for detecting whether user is using mobile data internet. Game asks you before downloading assets when you're using mobile data. New LoadingBar and LoadingStatusTexts.

 * gradle task for uploading SNAPSHOT assets package
 * using SNAPSHOT assets package only in devel build type and DEV versions

 * new api for loading texture regions from atlases
 * removed old texture loader
 * gradle tasks for assets preparing
 * gradle UP-TO-DATE task check
 * application new api fix
 * atlases automatic linear filtering
 * sound assets conversion to flat hierarchy
 * automatic global assets loading
 * automatic screen and game local assets loading

#14 Assets directory moved from ".tablexia" to ".tablexia/assets". Data directory moved from ".tablexia" to ".tablexia/data"

 * refactored mechanism of files access
 * new utility methods for file access

 * mechanism for calculating MD5 checksum for all directory (same mechanism used in ZipLoader and Gradle)

#23 removed application id from tablexia settings, application preferences file from build type name

 * Tablexia iOS version automatic build
 * automatic creation of debug and release build types
 * different application ID for debug and release build types

 * save last screen
 * restore last screen after start
 * reset saved screen on Android for app shutdown from task manager

 * aplication version attribute in jar manifest
 * load application version from jar or apk and display in debug info

 * automatic version name from git
 * automatic version code from last git commit timestamp
 * gradle packages naming

 * build variant connected to application settings

 * change screen event
 * application loading complete event