Changes as of Wednesday

Whew!

* Most globals wrapped into a pair of global HeaderData structs
* Saner mutex design, and ensures matching of image with header information
* Steve's PR (#131)
* Closes #130 (service restarts executable after an exit/crash)
* Closes #106 (fiducial and limb counts in header)

With the first two bullets, hopefully segmentation faults (e.g., #125) will no longer occur

Merging immediately