Fix a typo in build process
Make icns compatible from Leopard (10.5) to Mountain Lion (10.8)

oldiconutil tool (https://github.com/uliwitness/oldiconutil) was used.
Leopard cannot cache Icns bigger than 1 Mbyte; so for the app icon, I used the option --compression jp20.95
Use integrated method for displaying unread articles count in Dock.
Fix typo and comment
Handle icon badge when there is no unread articles left.
Merge pull request #164 from barijaona/bugfixes

Leopard compatible icon, leopard and better method for displaying unread articles count, and fix a typo in build process.