Add a good rotation example to Basis2.

This ads an example (the first?) on a useful feature of cgmath, and
also a Make target for running just the examples in the docs. This
may come in useful if more examples are added.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>
Added `doctest` to the Travis config.

This requires removing the `make clean` step, but I don't think this
will have any side effects.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>
Merge pull request #103 from atheriel/rot_ex

Add a rotation example to the documentation.
Remove crate_id.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Merge pull request #104 from omasanori/crate_name

Remove crate_id.
Implements division and remainder operators for vectors.

This might have been an oversight at one point. Although the `rem_v`
and `div_v` methods are available for vectors, the actual operators
were not.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>
Implements the (mutable) index operator for vectors.

Again, this is possibly an oversight. The operators simply use the
mut_i() and i() methods which are demanded by the Array1<S> trait.

This means you may access the field `x` on a VectorN with vector[0]
syntax.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>
Merge pull request #105 from atheriel/vec_ops

Actually implement division, remainder, and index operators for vectors.
Deprecate element and column accessors in favour of index operators

Also removes some unnecessary `clone` calls.
Merge pull request #107 from bjz/index-operators

Deprecate element and column accessors in favour of index operators