Import hard-coded curry with ES2015 modules and Rollup

[ghost]

Switches from Ramba's curryN to Most.js (@most/prelude) hard-coded curry2 and curry3 implementations. Part of the rationale.

I also saw potential in size reduction comparing the implementations: the changes result in fact in a 32% size drop on a minified + gzipped build.

I replaced Browserify with Rollup, which has had the side-effect of bringing down the bundle size even further.

Edit: The changes need Node >= 4.0.0.

[coveralls]

Coverage decreased (-0.9%) to 99.078% when pulling 566c71f on flagello:improve_curry into 8e78338 on paldepind:master.

[coveralls]

Coverage decreased (-0.9%) to 99.078% when pulling 90038e0 on flagello:improve_curry into 8e78338 on paldepind:master.

[coveralls]

Coverage decreased (-0.9%) to 99.078% when pulling 90038e0 on flagello:improve_curry into 8e78338 on paldepind:master.

[coveralls]

Coverage decreased (-0.9%) to 99.078% when pulling 8c3f25b on flagello:improve_curry into 8e78338 on paldepind:master.

[coveralls]

Coverage decreased (-0.9%) to 99.078% when pulling 8c3f25b on flagello:improve_curry into 8e78338 on paldepind:master.

[coveralls]

Coverage decreased (-0.9%) to 99.078% when pulling 93021f3 on flagello:improve_curry into 8e78338 on paldepind:master.