Bunch of fixes
- added .gitignore
- Added check if field 'query' exists in $returnURL. (Old code generated LOG messages if it was not set)
- Added check if field 'AuthID' exists in $query. (Old code generated LOG messages if it was not set)
- Added check if $state is not null. (Old code generated LOG messages if it was not set)
- Added check if field 'SPmetadata' exists in $state. (Old code generated LOG messages if it was not set)
- Added check if field 'query' exists in $returnURL. (Old code generated LOG messages if it was not set)