Add table for logger management

[jkall]

From [email protected] on February 11, 2014 12:50:37

Add a able "loggers" to the database to hold information about loggers used.

Column; Desc; Primary Key; Foreign Key obsid; Observation point identifier; 1; obs_points(obsid) instrumentid; Logger identifier; 1; status; Present/past/future – i.e. if this obsid-instrumentid exists right now, if it did earlier or if it is only a planned logger position; ; date_start; Logger started; ; date_stop; Logger will be full; ; Meas_int; Recording interval; ; Comment; ; ;

Original issue: http://code.google.com/p/midvatten-plugin-for-qgis/issues/detail?id=43

[jkall]

This is absolutely needed when introducing this: https://github.com/jkall/qgis-midvatten-plugin/issues/57