Feature/issue 214

Fixes #214.

These fixes are only in the echo string of two makefiles and in the c++ level doc of the compiler. No changes to code have been made.

The output now looks like:
```
> make src/models/basic_distributions/normal
...
--- Translating Stan model to C++ code ---
bin/stanc src/models/basic_distributions/normal.stan --o=src/models/basic_distributions/normal.cpp
...
```