Fixes problem with data sources.

Documentation/Schedulers.md

@@ -13,7 +13,7 @@ There are two main operators that work with schedulers, `observeOn` and `subscri
 
 If you want to perform work on a different scheduler just use `observeOn(scheduler)` operator.
 
-You would usually use `observeOn` a lot more often then `subscribeOn`.
+You would usually use `observeOn` a lot more often than `subscribeOn`.
 
 In case `observeOn` isn't explicitly specified, work will be performed on whichever thread/scheduler elements are generated.
 

RxCocoa/Common/DelegateProxyType.swift

@@ -178,14 +178,14 @@ extension DelegateProxyType {
         let maybeProxy = Self.assignedProxyFor(object) as? Self
 
         let proxy: Self
-        if maybeProxy == nil {
+        if let existingProxy = maybeProxy {
+            proxy = existingProxy
+        }
+        else {
             proxy = Self.createProxyForObject(object) as! Self
             Self.assignProxy(proxy, toObject: object)
             assert(Self.assignedProxyFor(object) === proxy)
         }
-        else {
-            proxy = maybeProxy!
-        }
 
         let currentDelegate: AnyObject? = Self.currentDelegateFor(object)
 

RxCocoa/iOS/Proxies/RxCollectionViewDataSourceProxy.swift

@@ -19,8 +19,10 @@ let collectionViewDataSourceNotSet = CollectionViewDataSourceNotSet()
 class CollectionViewDataSourceNotSet
     : NSObject
     , UICollectionViewDataSource {
+
+
     func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
-        rxAbstractMethodWithMessage(dataSourceNotSet)
+        return 0
     }
     
     // The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:

RxCocoa/iOS/Proxies/RxTableViewDataSourceProxy.swift

@@ -19,8 +19,9 @@ let tableViewDataSourceNotSet = TableViewDataSourceNotSet()
 class TableViewDataSourceNotSet
     : NSObject
     , UITableViewDataSource {
-    func numberOfSections(in tableView: UITableView) -> Int {
-        rxAbstractMethodWithMessage(dataSourceNotSet)
+
+    func numberOfSectionsInTableView(tableView: UITableView) -> Int {
+        return 0
     }
     
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
@@ -62,8 +63,8 @@ public class RxTableViewDataSourceProxy
     /**
     Required delegate method implementation.
     */
-    public func numberOfSections(in tableView: UITableView) -> Int {
-        return (_requiredMethodsDataSource ?? tableViewDataSourceNotSet).numberOfSections?(in: tableView) ?? 1
+    public func numberOfSectionsInTableView(tableView: UITableView) -> Int {
+        return (_requiredMethodsDataSource ?? tableViewDataSourceNotSet).numberOfSections?(in: tableView) ?? 0
     }
 
     /**