Detailed explanatory comments on major functions in wali/graph/

The comments include psuedocode for
InterGraph::setupNewtonSolution
IntraGraph::saturate
and description of the class
wali::graph::SemElemFunctional
Merge branch 'master' of https://github.com/WaliDev/WALi-OpenNWA
Fixed suggestions by Evan

Inclusion guard for header files
Change Witness::getLength to Witness::getMinimumLength
Removed a couple stale includes
Added some author info
Use new intersection algorithm, check for no final states in result
Merge branch 'master' of github.com:WaliDev/WALi-OpenNWA