Feature/s3 log uploader

changes:

-allow regex pattern matching to select files to upload
-allow to gzip files, which aren't gzipped yet and upload them (including the files that have already been gzipped)
-allow to specify a time_range (compares modification time of files within the source-directory), s3_uploader will only upload files, which cover the selected range
-allow to specify a 'gzip_working_dir': if using gzip you can point to a location where you have write permissions (to prevent filesystem-permission-problems), gzipped files will be stored there

-all features are optional
-current behaviour is untouched

-specs for each feature are added

L.Bratke