Remove dependency on curl

The core ownCloud libraries provide a getUrlContent() util which will
attempt to retrieve the contents of a URL using curl with a fall-back to
get_file_contents(). By using getUrlContent() we can remove curl as a
dependency, which is useful for servers that don't have it installed.
Merge pull request #33 from jerrykan/uncurl

Remove dependency on curl
split logic into business layers
small pixel fixes
put getUrlContent into api
added pluggable fetchers
added comments on ifeedfetcher
fix #11 by not relying on db exceptions anymore since there is no fking proper exception handling in the owncloud db code and stuff will break. instead update when item has been found and if not insert
added
added simple twitter fetcher implementation
add comment for twitter fetcher
remove app styles now they are in core
Merge pull request #34 from owncloud/remove-appstyles

remove app styles now they are in core