to handle TheOldReader
Simplify and fix fetching of feed icon.
Use variables to describe specific behaviors like TheOldReader.com's ones
Add TheOldReader.com to the list of supported servers
Rename the "Google Reader" group to "OpenReader"
Fix home page determination for feeds hosted by InoReader

InoReader does not provide the "alternate" information when we fetch a feed. So we need to make use of the "htmlUrl" information provided within the subscriptions list.
Optimization
In fact, homepage info might sometimes need update…
Merge pull request #273 from barijaona/TheOldReader

Support TheOldReader.com
Update version number to 3.0.0 RC 1
Detects and treat links to ebooks as enclosures

Request here : http://forums.cocoaforge.com/viewtopic.php?t=26520&p=138182
OPDS uses a variation of Atom feeds, with acquisition links : http://opds-spec.org/specs/opds-catalog-1-1-20110627/
Treat relative links for enclosures.

Related to http://forums.cocoaforge.com/viewtopic.php?t=26520&p=138182
Merge pull request #275 from barijaona/OPDS

OPDS support