Rename the `geom`, `Geom` to `shape` and `Shape`.

"Geometry" is not the correct name as it is a concept, not a thing. "Shape" is the correct one.

cc #32.
Rename `implicit` and `Implicit` to `support_map` and `SupportMap`.

cc #32.
Rename `narrow` to `narrow_phase`.

cc #32.
Rename `broad` to `broad_phase`.

fix #32.
Move `narrow_phase::algorithm` to `geometry::algorithms`.
Update to the last rust-nightly.

Version of rustc: 0.13.0-nightly (3327ecca4 2014-11-01 22:41:48 +0000).