Improve path* implementations
Set the contracts of path functions
Enable 'eqnull' jshint option
Merge pull request #114 from megawac/path

Improve path* implementations
Better String Representation for Compose

Similar to setSource but for 2 functions, setCompositeRepr creates a
string representation for the composed function in this style
```
function A (...)  {
//stuff
}

THEN

function B (...)  {
//stuff
}
```
More specifically, its the string represetnation of `A` separated by new
lines + `"THEN"` + new lines + the string representation of `B`, for the
funtion `compose(B, A)`.
Merge branch 'master' of https://github.com/CrossEye/ramda

Conflicts:
	ramda.js