Use possessive quantifiers in regex for decoding cookies

Decoding cookies becomes very complex to handle for the regex engine
when cookie values are very large. This causes `StackOverflowError`s
probable due to the catastrophic backtracking

Use possessive quantifiers to prevent the regex engine from trying
all permutations. This should make the complexity of the regex linear
and not exponential. The performance increase can be significant and
fixes the issue.

Closes #77

src/main/java/com/vtence/molecule/http/CookieDecoder.java

@@ -7,7 +7,7 @@
 
 public class CookieDecoder {
 
-    private static final Pattern NAME_VALUE_PAIR = Pattern.compile("(?:\\s|[;,])*([^;=]+)(?:=([\"]((?:\\\\\"|[^\"])*)[\"]|[^;,]*))?");
+    private static final Pattern NAME_VALUE_PAIR = Pattern.compile("(?:\\s|[;,])*+([^;=]++)(?:=([\"]((?:\\\\\"|[^\"])++)[\"]|[^;,]*+))?+");
 
     private static final int NAME = 1;
     private static final int VALUE = 2;

src/test/java/com/vtence/molecule/http/CookieDecoderTest.java

@@ -1,5 +1,6 @@
 package com.vtence.molecule.http;
 
+import org.hamcrest.Matchers;
 import org.junit.Test;
 
 import java.util.List;
@@ -132,6 +133,12 @@ public void decodesCommaSeparatedPairs() {
         assertThat("cookie value", launcher.value(), equalTo("Rocket_Launcher_0001"));
     }
 
+    @Test
+    public void handlesVeryLongCookieValue() {
+        Cookie cookie = decodeSingle("$Version=\"1\"; molecule.session=\"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--r3q1yut2aSCAjMF03DMV2z5A79aeWP744I2pMVoO7qk=\";$Path=\"/\";$Domain=\"0.0.0.0\"");
+        assertThat(cookie.value(), Matchers.endsWith("MVoO7qk="));
+    }
+
     private Cookie decodeSingle(String cookieHeader) {
         List<Cookie> cookies = decodeAll(cookieHeader);
         assertThat("cookies found", cookies, hasSize(1));