update elements and fix some bugs

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

 Prism.languages.scala = Prism.languages.extend('java', {
-        'keyword': /(<-|=>)|\b(abstract|case|catch|class|def|do|else|extends|final|finally|for|forSome|if|implicit|import|lazy|match|new|null|object|override|package|private|protected|return|sealed|self|super|this|throw|trait|try|type|val|var|while|with|yield)\b/,
-        'builtin': /\b(String|Int|Long|Short|Byte|Boolean|Double|Float|Char|Any|AnyRef|AnyVal|Unit|Nothing)\b/,
-        'number': /\b0x[\da-f]*\.?[\da-f\-]+\b|\b\d*\.?\d+[e]?[\d]*[dfl]?\b/i,
-        'symbol': /'([^\d\s]\w*)/,
-        'string': /(""")[\W\w]*?\1|("|\/)[\W\w]*?\2|('.')/
+        'keyword': /<-|=>|\b(?:abstract|case|catch|class|def|do|else|extends|final|finally|for|forSome|if|implicit|import|lazy|match|new|null|object|override|package|private|protected|return|sealed|self|super|this|throw|trait|try|type|val|var|while|with|yield)\b/,
+        'string': /"""[\W\w]*?"""|"(?:[^"\\\r\n]|\\.)*"|'(?:[^\\\r\n']|\\.[^\\']*)'/,
+        'builtin': /\b(?:String|Int|Long|Short|Byte|Boolean|Double|Float|Char|Any|AnyRef|AnyVal|Unit|Nothing)\b/,
+        'number': /\b(?:0x[\da-f]*\.?[\da-f]+|\d*\.?\d+e?\d*[dfl]?)\b/i,
+        'symbol': /'[^\d\s\\]\w*/
 });
 delete Prism.languages.scala['class-name'];
 delete Prism.languages.scala['function'];