Increased warning levels to -Wall -Wextra, and fixed Xcode 7 beta issues

Summary:
@public

I've increased the warning levels in the OSS frameworks, which caught a bunch of minor issues. I also fixed some new errors in Xcode 7 relating to designated initializers and TLS security.

Test Plan:
* Test the sample apps and make sure they still work.
* Run tests.

Libraries/WebSocket/RCTSRWebSocket.m

@@ -246,8 +246,9 @@ static __strong NSData *CRLFCRLF;
 
 - (instancetype)initWithURLRequest:(NSURLRequest *)request protocols:(NSArray *)protocols;
 {
+  RCTAssertParam(request);
+
   if ((self = [super init])) {
-    assert(request.URL);
     _url = request.URL;
     _urlRequest = request;
 
@@ -255,23 +256,24 @@ static __strong NSData *CRLFCRLF;
 
     [self _RCTSR_commonInit];
   }
-
   return self;
 }
 
+RCT_NOT_IMPLEMENTED(-init)
+
 - (instancetype)initWithURLRequest:(NSURLRequest *)request;
 {
   return [self initWithURLRequest:request protocols:nil];
 }
 
-- (instancetype)initWithURL:(NSURL *)url;
+- (instancetype)initWithURL:(NSURL *)URL;
 {
-  return [self initWithURL:url protocols:nil];
+  return [self initWithURL:URL protocols:nil];
 }
 
-- (instancetype)initWithURL:(NSURL *)url protocols:(NSArray *)protocols;
+- (instancetype)initWithURL:(NSURL *)URL protocols:(NSArray *)protocols;
 {
-  NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
+  NSURLRequest *request = URL ? [NSURLRequest requestWithURL:URL] : nil;
   return [self initWithURLRequest:request protocols:protocols];
 }
 
@@ -1610,7 +1612,7 @@ static NSRunLoop *networkRunLoop = nil;
     _runLoop = [NSRunLoop currentRunLoop];
     dispatch_group_leave(_waitGroup);
 
-    NSTimer *timer = [[NSTimer alloc] initWithFireDate:[NSDate distantFuture] interval:0.0 target:nil selector:nil userInfo:nil repeats:NO];
+    NSTimer *timer = [[NSTimer alloc] initWithFireDate:[NSDate distantFuture] interval:0.0 target:self selector:@selector(step) userInfo:nil repeats:NO];
     [_runLoop addTimer:timer forMode:NSDefaultRunLoopMode];
 
     while ([_runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]) { }
@@ -1618,6 +1620,11 @@ static NSRunLoop *networkRunLoop = nil;
   }
 }
 
+- (void)step
+{
+  // Does nothing
+}
+
 - (NSRunLoop *)runLoop;
 {
   dispatch_group_wait(_waitGroup, DISPATCH_TIME_FOREVER);

Libraries/WebSocket/RCTWebSocket.xcodeproj/project.pbxproj

@@ -151,6 +151,7 @@
 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED = YES;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
@@ -159,6 +160,10 @@
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
+				WARNING_CFLAGS = (
+					"-Werror",
+					"-Wall",
+				);
 			};
 			name = Debug;
 		};
@@ -187,6 +192,7 @@
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_INITIALIZER_NOT_FULLY_BRACKETED = YES;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
@@ -195,6 +201,10 @@
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				VALIDATE_PRODUCT = YES;
+				WARNING_CFLAGS = (
+					"-Werror",
+					"-Wall",
+				);
 			};
 			name = Release;
 		};
@@ -202,6 +212,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				EXECUTABLE_PREFIX = lib;
+				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				HEADER_SEARCH_PATHS = (
 					"$(inherited)",
 					/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include,
@@ -218,6 +229,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				EXECUTABLE_PREFIX = lib;
+				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				HEADER_SEARCH_PATHS = (
 					"$(inherited)",
 					/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include,

Libraries/WebSocket/RCTWebSocketExecutor.m

@@ -43,7 +43,9 @@ RCT_EXPORT_MODULE()
 
 - (instancetype)initWithURL:(NSURL *)URL
 {
-  if (self = [super init]) {
+  RCTAssertParam(URL);
+
+  if ((self = [super init])) {
     _url = URL;
   }
   return self;