Merge pull request #120 from dbickson/master

fixed missing end of dox sign at the graph analytics toolkit - thanks to...
Fix for a compiler issue on OSX ('value_type' is a private member of 'graphlab::discrete_domain::ConstIterator') which seems to be a LLVM bug (see http://llvm.org/bugs/show_bug.cgi?id=12240)
Merge pull request #121 from hstm/master

Fix for a compiler issue on OSX ('value_type' is a private member of 'gr...
correction for tutorial docs code
more tutorial code changes

another change to accompany #122 and #105
Merge pull request #122 from boorad/master

correction for tutorial docs code
fixed a documentation error thanks to omer b