Test data for grouped serial measurements

The original test result XML schema has attribute "group" for a series
element. It has not been used in QA Reports, and the original purpose of
the attribute is unknown (no documentation in the schema or in the
commit message, and since bugs.meego.com is no longer online the
original item cannot be checked).

So a brave choise is made to use this attribute for grouping serial
measurements together so that we can draw a graph showing more than one
data series in single graph.
Initial spec for parsing the example data file

When measurements are grouped expecting to get only one serial
measurement per test case.
Update selenium-webdriver
Initial combining of grouped series

We now collect series of a test case into two sets:
1) groups with more than one series (these are the "grouped series")
2) series without group attribute, and groups with only one series
   (these are not reported by the name of the group because of backwards
    compatibility)

The parser still does nothing for the grouped series, but all existing
tests pass and we can keep on going.
Spec for long_json to contain correct amount of data

Grouped measurements will have more values for each measurement in a
json series. Test that the amount of values is expected.
long_json is now constructed for grouped series

At least for a limit is imposed: the grouped series MUST all use either
interval/timestamp representation, and they must be clock aligned (same
interval and interval unit, or same timestamps), and the amount of
measurements must also match. This may possible change at some point.

Also, fixed test data timestamps
Create initial model for SerialMeasurementGroup

To get serial measurements grouped and have all the required information
nicely available the model hierarchy will be changed. A new model,
SerialMeasurementGroup comes in between MeegoTestCase and
SerialMeasurement.
Add serial_measurement_group_id to serial_measurements
Move serial measurements under serial measurement groups

Database migration and model changes for moving the existing serial
measurements under serial measurement groups
Move serial measurements under serial measurement groups
The small graphs and modals now work for groups

Fixed inline graphs and modal graphs to use the new data structure and
formats. NFT history still needs some love, then we can move on to crud
operations.
NFT history charts work now

NFT history charts are now back as they used to be. The modal graph
history is not yet ready for multi series charts.
Revert lib/nft.rb
XML result file parser should now produce expected hash
Fix an old bug

In some cases non-NFT results were not shown - eg. one non-NFT case, two
NFT cases that both have both serial and non-serial measurements gives a
total of 3 test cases, but due to the error in the total_nft
calculations total_nft reported 4 and this led has_non_nft? to return
false.
CRUD for serial NFT reports fixed

Now adding/deleting/merging/updating reports with
SerialMeasurementGroups should work.
Don't rely on whitespace being preserved
Fix factories to use the new SerialMeasurementGroup thing
Update DyGraph
Now modal graph for for two-axis serial measurements