LogAnalyzer add TestAutotune

Adds an autotune target, which can be used to make sense of the data in case autotune fails.

This is my own data:
              Autotune:  FAIL       [-] ATDE Angle:20 Rate:9867.21484375 ATUN RPGain:0.0100000072271 RDGain:0.00300000002608 SPGain:4.5 (@line:37519)    [GRAPH]
                                    [-] ATDE Angle:6 Rate:9201.97949219 ATUN RPGain:0.0100000072271 RDGain:0.0050000003539 SPGain:4.5 (@line:67101)
                                    incomplete autotune attempt started @91856

it fails when trying to lower P below 0.01 to get the rate down.

This is 201406172154331minihexautotunestopsfivetimes.log I found on diydrones blog:
              Autotune:  FAIL       [-] ATDE Angle:20.81 Rate:10071.92 ATUN RPGain:0.01412 RDGain:0.006 SPGain:3.0 (@line:4784)    [GRAPH]
                                    [-] ATDE Angle:20.15 Rate:9515.271 ATUN RPGain:0.01412 RDGain:0.006 SPGain:3.0 (@line:13189)
                                    [-] ATDE Angle:20.34 Rate:9667.557 ATUN RPGain:0.01412 RDGain:0.0055 SPGain:3.0 (@line:22244)
                                    [-] ATDE Angle:9.45 Rate:8655.21 ATUN RPGain:0.01412 RDGain:0.007 SPGain:3.0 (@line:32951)
                                    [-] ATDE Angle:10.44 Rate:8077.911 ATUN RPGain:0.01412 RDGain:0.007 SPGain:3.0 (@line:50222)

In case autotune works, it looks like this (20140616080715.log from diydrones):
              Autotune:  GOOD       [+] ATDE Angle:20.3 Rate:7921.739 ATUN RPGain:0.115 RDGain:0.014 SPGain:2.0 (@line:6343)

And in case there is no data:
              Autotune:  UNKNOWN    No ATUN log data                                       

For small (overpowered?) micro quads, autotune regulary fails, having this Test helps understanding the problem.