Added arguments to `knit2wp` to allow for editing (overwriting) pages rather than just creating new pages.  Also changed `getFromNamespace` to `do.call` as this allows more felxibiliy that is now needed for allowing editing.
Merge pull request #916 from jaredlander/master

Allow editing (overwriting) of WordPress posts and pages

[ci skip]
Added new option for newPage in addition to newPost and editPost.

Merge branch 'master' of github.com:yihui/knitr

Conflicts:
	R/utils-conversion.R