working draft for solver statistics.
Update lowlevel.rst
Update lowlevel.rst
Update lowlevel.rst
See JuMP/#244
add deprecated method; update docs.
update mixintprog
make backwards compatibility stub actually work.
Merge branch 'solver-stats' of git://github.com/JuliaOpt/MathProgBase.jl into solver-stats
Merge branch 'solver-stats'
merged in semicont
fix broken test.
fix lingering typo.