Improve config-galaxy-s2 process to make it without need for a real phone

[andreasgal]

Improve config-galaxy-s2 process to make it without need for a real phone

[joneschrisg]

It would be interesting to try just pulling all the blobs from the CM image and see if the resulting b2g image works. If not, for some compat reason, we can try pulling them from an older CM image.

[shianyow]

Pulling from CM 7.1 caused some error message in logcat and some process fail to run( tested Android build). Unfortunate the CM official site only keeps CM 7.1, no older version.

[shianyow]

Some users got SGS2 phone from operator, the firmware was gingerbread 2.3.3 (not supported by B2G) and no newer version available.

For this reason I looked at this issue again with current B2G.
Now I can get B2G running and making phone calls by extracting blobs only from CM 7.1. Most functions looks fine, except wifi, because CM has it's own modification on wifi and we need to figure out the difference.