A profile for early-checking of templates

[AbhinavK00]

This is more in line with C++0x concept design and other languages such as Swift, Rust, Haskell etc. Now that C++ has concepts, it would be nice to have a profile that performs early definition checking to function and class templates. This suggestion is inspired from a discussion on cppfront github here. While I could not convince Herb to add early definition checking to cppfront, it was clear that the feature does have a place in today's C++.