example tests show function and line number when compilation fails

Cleaned up the ops examples.

Regarding the commit message.. I changed the runExample function so that it creates a new function for each test with a name that includes
- the function it is trying to run the test for
- the line number from ramda.js

This way if it fails to compile the test, you will see in your stack trace something like `at Function.runExample.(anonymous function) [as runExample_R_useWith_543]` so it is easy to track down where things are going wrong.

If it is an actual assertion that fails, you will see the expression that was calculated, what it resulted in, and what the author thought it should have been.

Quick note, I think it is a good idea to use the `R.` version of the function in examples rather than any local function name, as the examples are used to generate the docs at ramdajs.com and it can be strange to see an example not actually use the function it is demonstrating (and of course compliation will fail if there is not actually a local function with that name).
As currently written, the semi-colon to the left of the //=> is required for the line to be actually tested (if no `;`, the line will simply compile and execute as it is still valid javascript, but the value will not be asserted)