Removed old (commented-out) code
Added logger for install logs
Added directory for log files

* Added log dir to .gitignore
* Put .gitkeep in log dir
* Added section for .gitkeep files in .gitignore
Logger throws exception when logfile already exists
Made setup.php executable
Enabled rollback functionality

* Added option to force installation
* Force installation triggers rollback if installation already detected
* Install path will now be validated to use only single '/'
Added uninstall routine

* Install log is now written inside the installation directory
* New method _getInstallPath() to validate install path
* Removed logs directory under setup
Fixed uninstaller throwing warnings when logfile not found