added init.fsx to generate build.fsx from template

the build.template file is a tokenized version of build.fsx

this pull request is NOT done, just want to get the ball rolling here

this is pursuant to #22 
Should this be "mono packages/FAKE/tools/FAKE.exe $@ --fsiargs -d:MONO build.fsx"

Any args given in $@ are FAKE args, not F# Interactive args?  e.g. arguments like build targets such
 
    ./build.sh MyTarget