Add user switching methods in order to access user by org id and community ID. Still WIP

Conflicts:
	shared/SalesforceNetworkSDK
Update account manager to retrieve org IDs
Added comments and todos
Temporary code to switch users in orgs for Spring '14
Add method to retrieve array of accounts that match an org ID
Remove the first-object logic.
This leaves simply the aggregation into array methods that are useful and the consumer of the MobileSDK can then interact with the data however it prefers.

Conflicts:
	shared/SalesforceSDKCore/SalesforceSDKCore/Classes/Security/SFUserAccountManager.m
Splitting properties from identity data
Making some properties copy instead of readonly.
Merge pull request #553 from khawkins/misc_updates

Misc updates