Fix makefile - steganos now actually builds

Executable was not being linked, Makefile builtin rules for linking .o
files are only applicable with "foo: foo.o".
Fix file permissions

Text files should not be executable
Remove compiled binary from repo
Add STDIO data handlers

Refactor ICursesDataHandler -> IDataHandler
Enable selecting STDIO handlers from main
Merge pull request #1 from lutzky/master

Actual building + STDIO