#59 Improvements to the net plugin

[José Romildo Malaquias]

The attached patch improves the net plugin in three ways:

1) adds an option to the configuration to set the interface to be monitored; the configuration variable is called "Interface"

2) adds an option to the configuration to set the polling interval time (in microseconds); the variable is called "PollingTime"

3) the tooltip shows interesting information: the upload and download speed, and the total data transfered so far.

Please, if the code is ok, apply the patch to upstream.

[José Romildo Malaquias]

fbpanel.net-interface.patch