Add new methods to NSString extensions 2 of 2

New methods for stripping leading and/or trailing characters from string.

src/Core/NSStringOOExtensions.m

@@ -149,6 +149,36 @@ - (uint32_t) oo_hash
 	return hash;
 }
 
+
+- (NSString *)stringByTrimmingLeadingCharactersInSet:(NSCharacterSet *)characterSet
+{
+	NSRange rangeOfFirstWantedCharacter = [self rangeOfCharacterFromSet:[characterSet invertedSet]];
+	if (rangeOfFirstWantedCharacter.location == NSNotFound)  return @"";
+
+	return [self substringFromIndex:rangeOfFirstWantedCharacter.location];
+}
+
+
+- (NSString *)stringByTrimmingLeadingWhitespaceAndNewlineCharacters
+{
+	return [self stringByTrimmingLeadingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+}
+
+
+- (NSString *)stringByTrimmingTrailingCharactersInSet:(NSCharacterSet *)characterSet
+{
+	NSRange rangeOfLastWantedCharacter = [self rangeOfCharacterFromSet:[characterSet invertedSet] options:NSBackwardsSearch];
+	if (rangeOfLastWantedCharacter.location == NSNotFound)  return @"";
+
+	return [self substringToIndex:rangeOfLastWantedCharacter.location+1]; // non-inclusive
+}
+
+
+- (NSString *)stringByTrimmingTrailingWhitespaceAndNewlineCharacters
+{
+	return [self stringByTrimmingTrailingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+}
+
 @end