Rename additional C bindings defined in `cytoolz.cpython`

This differentiates the additional bindings with a common convention.
Currently, we only change bindings to return pointers instead of Python
objects, and we change the name from "Py*" to "Ptr*".  I expect we will
add more bindings in the future, including passing pointers to functions.
In this case, the name should be something like "*_ptr".
Simplify TravisCI script, which makes travis finish faster

I test installation with the C files that *I* create using this branch:

https://github.com/eriknw/cytoolz/tree/check_my_c_files

Hence, we don't need to verify that cytoolz can be installed with only a
C compiler for every commit.
Support serialization of curry, compose, juxt, and complement objects.
Merge pull request #34 from eriknw/rename_c_bindings

Rename additional C bindings defined in `cytoolz.cpython`
Merge pull request #35 from eriknw/simplify_travis

Simplify TravisCI script, which makes travis finish faster
Merge pull request #36 from eriknw/serialize

Support serialization of curry, compose, juxt, and complement objects.
Update `curry` and `reduceby` to match those in toolz

Matches curry changes from pytoolz/toolz#170
Matches reduceby changes from pytoolz/toolz#184
Use op-code constants `Py_EQ` and `Py_NE` for rich comparisons
Merge pull request #37 from eriknw/update_curry_reduceby

Update `curry` and `reduceby` to match those in toolz
Add `cytoolz.utils.consume` to efficiently consume iterators.

It was moved from `cytoolz.itertoolz._consume`.
`toolz` does not have `consume`.
Merge pull request #38 from eriknw/utils_consume

Add `cytoolz.utils.consume` to efficiently consume iterators.
Merge branch 'master' into join

Conflicts:
	cytoolz/itertoolz.pyx
	cytoolz/tests/test_itertoolz.py