Merge pull request #37 from demands/documentation_fix

Fix documentation for groupBy to indicate `pluck`-style syntax
fixed a small typo
implemented takeWhile and dropWhile
added skip as an alias for drop
starting to fiddle around in preparation for a new doc generation tool
working on cleaning up examples for API docs
Breakneck will use this
added Rake task for generating docs

One of these days I'll move to Grunt or something
added handling of ObjectLikeSequence for equality checks
incorporated nav resizing from current site
added selection of current nav link from current site
added lots of examples
updated gen:docs task w/ only certain sequence types
implemented custom docs CSS (mostly taken from current site)
tweaked some column widths
added benchmarks to API docs for where, sortBy, uniq, and zip
added Lazy.noop and Lazy.identity (really not important)
re-implemented drop the normal way
re-implemented reverse the normal way
working on getting rid of CachingSequence