Added AbstractAccount as parent class for accounts

- all methods defined in HRAbstractAccount need to be overriden by subclass
Added upload to flickr and dropbox classes

- upload images is now working
Merge pull request #13 from shahmharsh/Harsh

Added AbstractAccount as parent class for accounts, upload working
Merge branch 'master' into Rakshit

Conflicts:
	.DS_Store
	SharePic.xcodeproj/project.pbxproj
	SharePic/HRProfileDetailViewController.h
	SharePic/HRProfileDetailViewController.m