galaxys2-common: fix EXIF data generated by the camera

 * ensure that all IFDs are 12 bytes long; previously when the data field contained less than 4 bytes of data the IFDs were truncated too soon
 * change all data types and number of components according to the EXIF standard
 * get the actual status of the flash from the camera; previosly the camera flash settings (which are not valid EXIF values) were copied in
 * fix calculations of GPS coordinates

With these changes the EXIF generated by the camera are valid and readable. There are still issues with some tags but most data is correct now.

Thanks to dafnis, who identified the problematic fields, and tryptophane, who helped testing.

Patch Set 2: fix whitespaces.

Change-Id: I513ea89f69ff26646e6a4a439b1cd5b835cba8d6
galaxys2-common: camera: exynos_exif.c: fix values of some wrong EXIF tags

 * adapt the code to the changes made in Exif.h
 * calculate ExposureTime from the ShutterSpeedValue: the exposure time
   read from the camera doesn't seem to work

Together with changes in Exif.h, this commit fixes ExposureTime, FNumber,
ShutterSpeedValue, ApertureValue, BrightnessValue and MaxApertureValue.

The values now match what was generated by the closed camera driver.

Credits to tryptophane for ExposureTime and ShutterSpeedValue. Thanks to
opaco23 and stone_ship who provided samples.

This commit requires http://review.cyanogenmod.org/37370

Change-Id: I16b606e65e895b98f9679ffb6172869c2cbe741c
galaxys2-common: add secondary dependency

Change-Id: Icd1567c78a108d8cf1f204a8b8b3ce8802e1f4ec