Parser changing

added new function:readNextData to reuse reading method for GGAParser.
gpsFetch cleaned

gpsFetch function was so dirty, so I constructed from the first.
gpsFetch has also bug that can only parse one line at a time.
The timing to load data from gps and write to lcd or SD should be
considered.
Merge commit '1b1330573cbff87f49ba036b38651acd765508fb'

commits the changes about gps Fetch.
gps Fetch cleaned