initial callback work
forgot file
register callbacks
get current solution inside callback
lazyConstraint function
fix
fix registering callbacks
fix registering callbacks
Working prototype of TSP with callbacks
Merge branch 'master' of git://github.com/IainNZ/JuMP.jl into callbacks

Conflicts:
	src/JuMP.jl
Merge branch 'callbacks' of git://github.com/IainNZ/JuMP.jl into callbacks
update for bitrot
Merge branch 'master' into callbacks
update for MathProgBase callback interface
Merge branch 'master' into callbacks
Added simplelazy example, used in docs
Callbacks documented, examples done
Tweaks
Really tidied up TSP example
Added link to blog to docs