add optional foreground color to config
Merge branch 'unstable' of https://github.com/wpeter-sfdc/SalesforceMobileSDK-Windows into unstable

Conflicts:
	SalesforceSDK/Salesforce.SDK.Phone/Source/Pages/AccountPage.xaml.cs
	SalesforceSDK/Salesforce.SDK.Store/Source/Pages/AccountPage.xaml.cs
	SalesforceSDK/Salesforce.Sample.NativeSmartStoreSample/Salesforce.Sample.NativeSmartStoreSample.Shared/settings/Config.cs
	SalesforceSDK/Salesforce.Sample.SmartSyncExplorer/Salesforce.Sample.SmartSyncExplorer.Shared/settings/Config.cs