add envir argument for blogify and parse_pages
fix update_li_classes
add preliminary support for onefile
add .git to .Rbuildignore
add helper functions for blogify
update blogify to use helper functions added.
update slidify.Rproj
bump version to 0.4.1
set onefile to be FALSE by default
format pubDate correctly for RSS feeds.
allow ... arguments to be passed to render_page
use return_page = TRUE for blogify.
bump version to 0.4.5
add .travis.yml and update .Rbuildignore

Merge remote-tracking branch 'github'

Conflicts:
	.Rbuildignore