Added parsing of options (--log flag) with getopt
Added FLAGS reference to the usage
Added log function and replaced old echo statements

The log function automatically appends the output to the log file if the logging flag is set.
Added the --log option to the README and manual pages
Added the time logging

Now logging the start time at the begin of the backup and the elapsed time at the end of the backup.
Added version tracking

Added the VERSION global variable which is added to the log.
Better formatting of the elpased time
Merge branch 'time-logging' into version-logging
Changed version string to 0.2