update elements and fix some bugs

lib/src/prism/components/prism-objectivec.js

Index: lib/src/prism/components/prism-objectivec.js
diff --git a/lib/src/prism/components/prism-objectivec.js b/lib/src/prism/components/prism-objectivec.js
index 5f5db4bc26650b138c8e31fa3861db3005c89a10..0471d109647eecbfbc0cb51df42541d1b6b1467f 100644
--- a/lib/src/prism/components/prism-objectivec.js
+++ b/lib/src/prism/components/prism-objectivec.js
@@ -1,5 +1,5 @@
 Prism.languages.objectivec = Prism.languages.extend('c', {
-	'keyword': /(\b(asm|typeof|inline|auto|break|case|char|const|continue|default|do|double|else|enum|extern|float|for|goto|if|int|long|register|return|short|signed|sizeof|static|struct|switch|typedef|union|unsigned|void|volatile|while|in|self|super)\b)|((?=[\w|@])(@interface|@end|@implementation|@protocol|@class|@public|@protected|@private|@property|@try|@catch|@finally|@throw|@synthesize|@dynamic|@selector)\b)/,
-	'string': /(?:("|')([^\n\\\1]|\\.|\\\r*\n)*?\1)|(@"([^\n\\"]|\\.|\\\r*\n)*?")/,
-	'operator': /[-+]{1,2}|!=?|<{1,2}=?|>{1,2}=?|\->|={1,2}|\^|~|%|&{1,2}|\|?\||\?|\*|\/|@/
+	'keyword': /\b(asm|typeof|inline|auto|break|case|char|const|continue|default|do|double|else|enum|extern|float|for|goto|if|int|long|register|return|short|signed|sizeof|static|struct|switch|typedef|union|unsigned|void|volatile|while|in|self|super)\b|(@interface|@end|@implementation|@protocol|@class|@public|@protected|@private|@property|@try|@catch|@finally|@throw|@synthesize|@dynamic|@selector)\b/,
+	'string': /("|')(\\(?:\r\n|[\s\S])|(?!\1)[^\\\r\n])*\1|@"(\\(?:\r\n|[\s\S])|[^"\\\r\n])*"/,
+	'operator': /-[->]?|\+\+?|!=?|<<?=?|>>?=?|==?|&&?|\|\|?|[~^%?*\/@]/
 });