Fix nested Logger.measure

[dresselm]

I, [2013-01-26T13:35:07.246554 #8845]  INFO -- : Finished Simple in 0.000891s
I, [2013-01-26T13:35:07.246595 #8845]  INFO -- : Begin Html...
I, [2013-01-26T13:35:07.246634 #8845]  INFO -- : Finished Html in 1.0e-06s
I, [2013-01-26T13:35:07.246678 #8845]  INFO -- : Finished Reporting in 0.00163s
 => [[Mscan::Report::Simple, Mscan::Report::Html], 0.00163] 

The output should return the individual times and the total times something like this:

I, [2013-01-26T13:35:07.246678 #8845]  INFO -- : Finished Reporting in 0.000892s
 => [ [ [Mscan::Report::Simple, 0.000891], [Mscan::Report::Html, 1.0e-06] ], 0.000892]