Optimized version for possible to update without merge or destroy local config and better debugging posibilities

[karl007]

• rename update.php to index.php (sadly the diff shows as delete and add), so dont require /update/update.php
• move all configuration requirements to config.php which is not in git for better updates
• add CT_ROOT_DIR and BACKUP_DIR to customize the behaviour - default ist ../ and ../_BACKUP and the updater is in CT/update/
• add ENABLE_PUSH const as required to enable push, otherwise its disabled
• add DEBUG and logMsg() for more verbose output and debugging
• disable PHP timelimit - this could be an issue on some hosters
• remove createHash.php and auto generate Hash and show example config.php on the first run
• delete extracted dir on Exception, to prevent doing an manual remove if something failed
• update Readme