- fix ignoring input lines with 'nan'
 - did not work on SL6 w/ gcc

 Added one more if statement: If the track went into new Volume, then extracted the hit in previous Volume, and start a new hit in this current Volume. And in this current process, also allow the same following treatments for the new hit.

Update doxygen information for some undocumented classes. Add licence header to files where not present.

Update doxygen information for some undocumented classes. Add licence header to files where not present.