added executable to format log files

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
feature: added convertor from json (log file format) to logevent in zlog

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
created a cli module to handle cli input and provide formatted output

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
feature: support reading log files for zlog formatter

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
moved out cli module to own file in lib

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
zlog: determine if a file parameter is given, otherwise print the help and an error

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
zlog: verify that the file exists before trying to format it

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
zlog: added code comments

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
renamed :format to :layout for all layouts

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
updated readme with corrected heading depth + new zlog utility executable

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
version bump to 0.8

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>