Added a misc tasks module that for now contains an echo task
Added a simple interactive console for running goals
Make the console an "interactive" option of the build function
Merge branch 'master' of https://github.com/vietj/ceylon.build into console
Use mergeGoalSetsWithGoals to linearize Goal and GoalSet
when displaying available goals in console
Add check for Ctrl + D to quit the console
Use HashMap instead of LazyMap
Replace `interactive` argument for `build` function by --console option

This will allow to choose between launching the console or the engine
when launching the build module instead of being hardcoded in
build module
Documentation for console