User cuts support
Added user cut example
Test for user cuts for Gurobi
NEWS update
Documentation for user cuts
Tweak to comment in example
Callback test re-write
Finished refactor
load and test all available solvers for callbacks
src/solvers.jl (mostly) solver agnostic
debug artifact
full coverage on quad testing
cleaner way to check solver type
another little tweak to solver type checking
Merge branch 'master' into callbacks
I like macros, but we can use a function here
change in MathProgBase function call for quad obj
update docs for solver-independent QPs. Closes #27